NAIROBI, Kenya -- NAIROBI, Kenya (AP) — When the shooting began at the Nairobi mall, Cynthia Carpino and her husband hid in the parking lot. But their 1-year-old daughter wouldn't stop crying. To muffle her cries, her father placed his hand over her mouth so hard she almost suffocated. Little Azzurra fainted in his arms, and three weeks later she's still not right.

"Now when I try to put a sweater on her, and it goes over her mouth, she starts screaming and screaming," says Carpino. "I know this is because of what happened at the mall. But I don't know what to do about it."

Nor do other parents whose children were caught in the Westgate Mall horror on Sept. 21 and who are now grappling with how to help their traumatized children at the same time that they themselves are struggling with signs of distress.

The attackers struck on a Saturday afternoon, a time when families flock to the mall. Couples pushed strollers through marbled floors that would soon turn red with blood. Mothers with toddlers in tow loaded groceries into shopping carts at the supermarket, the same carts which would be used hours later as gurneys to evacuate the more than 60 dead.

When the assault started, parents threw themselves over their children to shield them, but they couldn't block out the sights and sounds. Now the psychological toll is becoming apparent. Girls draw pictures of grenades and machine guns. Kids who once played hide-and-seek are "playing Westgate," impersonating the terrorists. Yet some children who were directly in the line of fire are showing few, if any, symptoms, creating a confusing array of responses, sometimes within the same household.

Cynthia Carpino, a Kenyan, and her Italian husband, Livio, had just parked their car and were pushing their two-seater pram up the ramp leading to the mall's rooftop terrace. When the shooting erupted, Cynthia grabbed her 12-day-old baby while her husband held Azzurra. They ran in separate directions. Cynthia slipped under a parked car, the baby cradled in her arm.

Frightened shoppers tried to squeeze in after her. The terrorists spotted them and sprayed the car, until the young mother was surrounded by a buffer of corpses. The car began leaking water, drenching her. Her baby began to wail.

"Whenever they heard a baby cry, they would throw a grenade. Then you didn't hear the cries anymore," said Carpino. "I saw the feet of one go by. He said, 'We are al-Shabab. Your president has invaded our country. Our women are being raped. Our kids are being killed. So why should we spare your kids?' And then he opened fire."

Later al-Shabab, al-Qaida's affiliate in Somalia, would claim responsibility, saying the attack was in retaliation for Kenya's deployment of troops into Somalia, its neighbor.

Terrified that she might be spotted, Carpino opened her shirt and tried to get her baby to nurse under the chassis of the car. Each time the infant whimpered, she shoved its face into her chest, smothering the sound.

Meanwhile, her husband had ducked behind an enclosure and was struggling to calm their older daughter. When he put his hand across her mouth, she struggled. Then then went limp.

The family survived, though they now find themselves in different worlds. Livio Carpino has gone back to his job as pilot for Kenya Airways, while his wife is afraid to leave the house. Even though both her children were smothered, her baby appears unaffected, while Azzurra struggles with tasks as simple as getting dressed.

Clinical psychologist Katie McLaughlin, whose research at the University of Washington in Seattle focuses on post-traumatic stress disorder, or PTSD, says trauma alters the chemistry of the brain. So Azzurra would associate something touching her face with her panic during the attack. "It's typical conditioning," McLaughlin says, and for most people it fades over time.

It's when this process fails to happen that PTSD can set in, she said in a telephone interview. PTSD is more than ordinary stress. It's associated with severe or unusual trauma. Those experiencing it may suffer from violent, intrusive thoughts. They have trouble sleeping. Once innocuous things, like a particular smell or sensation, can bring back terrible memories. In the community of Newton, Conn., for instance, signs ask people to close doors softly because loud bangs still bring on flashbacks, nearly a year after a gunman opened fire inside the Sandy Hook Elementary School.

A number of factors determine why even siblings can have diametrically opposed reactions to the same experience.

Keya and Kashvi Sarkar, 9-year-old twin sisters, came away with very different reactions to the attack, and what they saw may explain why. The sisters, amateur cooks, couldn't wait to get to the mall and compete in the second round of the SunGold SunRice Super Chef Junior Competition.

They had put on their white chef hats and blue aprons, and had taken their seats, waiting for their turn at the cutting board. When their mother tried to linger, she was told parents had to stay outside. So she left, and when the first explosion went off, the girls found themselves alone.

In desperation they ran to the far end of the parking lot, huddling against the wall. Keya got there first and managed to squeeze between two large women, her body shielded by theirs. Kashvi got there too late, and was left on the edge of the cowering crowd, directly exposed to the gunmen. She lay on the pavement and closed her eyes.

By contrast, Keya kept looking: "I saw three men. Three terrorists. They were wearing black turbans ... They were just shooting at anyone that moved," she said. "There was a lady with a baby next to me. When the baby started crying, they threw a grenade at us. It bounced over a car and landed next to my sister. The only grenade I'd seen before was on Tom & Jerry."

The grenade rolled to a stop. It began giving off a black, acrid smoke. Just feet away, Kashvi stayed face down, never looking up. Keya covered her head with her arms and waited for the blast, which never came.

When it didn't go off she stole a peek. The peek turned into a stare. By the time they were evacuated she'd been looking at the grenade for so long that when the therapist asked her to draw it, she could replicate its exact shape, down to its ovoid shell and L-shaped lever, her parents said.

By contrast her sister, who was far more exposed, showed no desire to draw pictures of what she'd seen. At school, when their teacher gave them the choice of writing about Westgate or about a trip to space, Keya chose Westgate, carefully detailing what had happened. Her sister wrote about a voyage around the cosmos.

It's indicative of how powerful images are in the trauma registered by children, says psychologist Dr. Jonathan Comer, who is leading a study surveying the responses of hundreds of youth to the Boston Marathon bombing.

"One kept her eyes open. One kept her eyes closed. It may seem that these two girls had a very similar experience, but experience is multisensory. The fact that one girl did not witness some of the horror visually means she had a smaller dose of traumatic exposure," said Comer, who heads the Mental Health Interventions and Technology Lab at Florida International University.

Many U.S. school districts now instruct children to walk out with their eyes closed from situations like the Sandy Hook Elementary School shooting in Connecticut last year, he said. This is specifically because there is mounting evidence of the potential harm of seeing terrible things.

Similarly, after the Sept. 11, 2001 attacks, researchers found that children were being traumatized simply by watching TV coverage of the event, says Dr. Lawrence Amsel, an assistant professor of clinical psychiatry at Columbia University. According to one 2005 study, 8 percent of children in Seattle showed signs of possible PTSD even though their only connection to the attacks was the nightly news.

After Westgate, schools throughout Nairobi as well as private professionals offered free counseling. Therapists are encouraging kids to draw what they saw, or play out what happened, while coaxing them to imagine a different outcome and absorb a new narrative.

Clinical psychologist Dr. Stephen Wahome has seen many of the victims, including Keya and Kashvi.

"I say to them, 'Let's play Westgate.' And they grab a stick and say it's a gun, or they hide behind something and say they are the terrorist. It can bring on discussion. It's a way to get it out of them. It becomes less painful. I talk to them, and say, 'OK so the terrorist went there? Where could you have gone to get away?'"

Wahome concluded: "Trauma is a scar. It doesn't go away. What you do is you can make it become smaller and smaller. When you work on it, it becomes less painful, and eventually you learn to live with it."

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  • A plume of black smoke billows over the Westgate Mall, in Nairobi, Kenya Monday, Sept. 23, 2013. Multiple large blasts have rocked the mall where a hostage siege is in its third day. Associated Press reporters on the scene heard multiple blasts and a barrage of gunfire. Security forces have been attempting to rescue an unknown number of hostages inside the mall held by al-Qaida-linked terrorists.(AP Photo/Jonathan Kalan)

  • Armed police from the General Service Unit take cover behind a wall during a bout of gunfire, outside the Westgate Mall in Nairobi, Kenya Monday, Sept. 23, 2013. Hostages being held by al-Qaida-linked terrorists in a Nairobi mall have not been released despite an earlier statement from the military that "most" had been rescued, a person connected to the situation told The Associated Press on Monday. (AP Photo/Ben Curtis)

  • Paramedics and police officers run outside the Westgate Mall in Nairobi after heavy shooting started Monday, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff. (AP Photo/Sayyid Azim)

  • Kenya security forces are seen behind a wall outside the Westgate Mall in Nairobi, Kenya Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Jerome Delay)

  • Kenya security personnel take cover outside the Westgate Mall after shooting started inside the mall early Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Sayyid Azim)

  • Kenya security forces are seen behind a wall outside the Westgate Mall in Nairobi, Kenya Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Jerome Delay)

  • Kenya security forces are seen behind a wall outside the Westgate Mall in Nairobi, Kenya Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Jerome Delay)

  • Onlookers gather on a hill to observe the Westgate Mall after a bout of heavy gunfire just after dawn in Nairobi, Kenya Monday, Sept. 23, 2013. Helicopters circling overhead, Kenya's military launched a major operation Sunday night at the upscale Nairobi mall and claimed it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during a standoff that killed at least 68 people and injured 175. (AP Photo/Ben Curtis)

  • Relatives wait at the Nairobi City Mortuary following the mall attack in Kenya, Sunday, Sept. 22, 2013. Kenyan authorities said Islamic extremist attackers remain inside the upscale Kenyan shopping mall, holding an unknown number of hostages, after killing at least 39 and injuring 150 during Saturday's attack. (AP Photo/Khalil Senosi)

  • Groups of onlookers gather on a road looking down over the Westgate Mall in Nairobi, Kenya Sunday, Sept. 22, 2013. Multiple barrages of gunfire erupted Sunday morning from the upscale Kenyan mall where there is a hostage standoff with Islamic extremists nearly 24 hours after they attacked using grenades and assault rifles. (AP Photo/Ben Curtis)

  • A line of soldiers from the Kenya Defense Forces run in front of the Westgate Mall in Nairobi, Kenya Sunday, Sept. 22, 2013. Multiple barrages of gunfire erupted Sunday morning from the upscale Kenyan mall where there is a hostage standoff with Islamic extremists nearly 24 hours after they attacked using grenades and assault rifles. (AP Photo/Ben Curtis)

  • Soldiers from the Kenya Defense Forces carry a wounded colleague, following the sound of explosions and gunfire, out of the Westgate Mall in Nairobi, Kenya Sunday, Sept. 22, 2013. Associated Press journalists at the scene of a hostage standoff said a barrage of gunfire erupted from the upscale Kenyan mall Sunday morning and moments later two wounded Kenyan security forces were carried out of the mall. (AP Photo/Ben Curtis)

  • Trucks of soldiers from the Kenya Defense Forces arrive after dawn outside the Westgate Mall in Nairobi, Kenya Sunday, Sept. 22, 2013. Islamic extremist gunmen lobbed grenades and fired assault rifles inside Nairobi's top mall Saturday, killing dozens and wounding over a hundred in the attack. Early Sunday morning, 12 hours after the attack began, gunmen remained holed up inside the mall with an unknown number of hostages. (AP Photo/Ben Curtis)

  • Trucks of soldiers from the Kenya Defense Forces arrive after dawn outside the Westgate Mall in Nairobi, Kenya Sunday, Sept. 22, 2013. Islamic extremist gunmen lobbed grenades and fired assault rifles inside Nairobi's top mall Saturday, killing dozens and wounding over a hundred in the attack. Early Sunday morning, 12 hours after the attack began, gunmen remained holed up inside the mall with an unknown number of hostages. (AP Photo/Ben Curtis)

  • Armed special force aim their guns at the Westgate Mall in Nairobi, Kenya on Saturday, Sept. 21 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted(AP Photo/Khalil Senosi)

  • Civilians who had been hiding inside during the gun battle manage to flee from the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • A body is seen on the floor, below right, as smoke fills the air inside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • A woman who had been hiding during the gun battle runs for cover after armed police, seen behind, enter the Westgate Mall in Nairobi, Kenya, Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • An armed police officer takes cover during a bout of gunfire outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Ben Curtis)

  • People run from the Westgate Mall in Nairobi, Kenya.

    Gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted.

  • A woman who had been held hostage reacts after being released.

    Suspected terrorists engaged Kenyan security forces in a drawn out gun fight at the Westgate Mall in Nairboi.

  • Woman runs for cover.

    A woman who had been hiding during the gun battle runs for cover after armed police, seen behind, enter the Westgate Mall in Nairobi, Kenya, Saturday, Sept. 21, 2013.

  • Location of the attack.

    Graphic shows detail of shopping mall site of fatal gun attack in Nairobi, Kenya.

  • View inside the mall.

    Armed police take cover behind escalators as smoke fills the air inside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013.

  • Raw: Gunmen Attack Shopping Mall in Kenya

    Gunmen threw grenades and opened fire at an upscale mall in Kenya's capital on Saturday, killing at least 10 people.

  • Armed police on scene.

    Armed police leave after entering the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013.

  • Mall-goers flee after attack.

    Civilians who had been hiding inside during the gun battle manage to flee from the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013.

  • An armed police officer takes cover during a bout of gunfire outside the Westgate Mall.

    The mall in Kenya's capital was hosting a children's day event at the time of the attack, a Red Cross official and witnesses said.

  • Armed police at the Westgate Mall.

    Armed police crouch down and take position during a gun battle outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013.

  • Civilians leave the mall after gun battle.

    Civilians who had been hiding during the gun battle hold their hands in the air as a precautionary measure before being searched by armed police leading them to safety, inside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013.

  • A rescue worker helps a child outside the Westgate Mall.

  • Security helps a woman outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded.

  • People flee the scene of the attack.

    Security helps people outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded.

  • A wounded man is escorted away from the mall.

    Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall.

  • A rescued hostage collapses on the ground after being freed by police at Westgate Mall.

    A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted.

  • Two women hug outside the mall after the attack.

    Bursts of gunfire were heard from outside the Westgate Mall Saturday, where cars were left abandoned. Witnesses say a half dozen grenades also went off along with lobbies of gunfire that started at midday.

  • Woman escapes from the Westgate Mall.

    A woman who had been hiding inside and managed to flee, sits in a state of shock, as an unidentified armed member of the security forces, above, keeps watch outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013.

  • Security officers keep a crowd under control outside the Westgate Mall

  • An injured person makes a phone call as he is helped on his arrival at the Aga Khan Hospital after the attack at the Westgate Mall.

  • An injured person arrives at the hospital after the attack on the Westgate Mall.

  • A injured child is wheeled away on a shopping trolley outside the Westgate Mall.

  • A security officer helps a wounded woman outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • An injured man arrives at the Aga Khan Hospital in Nairobi after the attack at the Westgate Mall.

  • An injured man arrives at the Aga Khan Hospital after the attack at the Westgate Mall.

    A witness to the attacks says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. Initial police reports had described the incident as a botched robbery. Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall.

  • A security guard helps a child outside the Westgate Mall.

    A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted.