05/02/2011 06:47 pm ET | Updated Jul 02, 2011

Osama Bin Laden Is Dead, But New York's Security Worries Live On (VIDEO)

At the news of Osama bin Laden's death a crowd of joyful New Yorkers gathered for a spontaneous celebration just outside the World Trade Center construction site late Sunday night. They were joined by a troop of smiling but serious New York Police Department officers.

Osama bin Laden's death may give some New Yorkers a sense of justice, but it won't necessarily change much about their daily lives. The mood city and state officials are projecting is a mix of satisfaction and post-Sept. 11 business as usual -- the city's security barriers will not be torn down any time soon.

"As of now, I'm happy to say, there are no new immediate threats against our city, but there is no doubt we remain a top target, and the killing of bin Laden will not change that," Mayor Michael Bloomberg said at a Ground Zero press conference Monday.

He was joined by NYPD Commissioner Ray Kelly, who said the department was "not taking any chances." He continued, "Our assumption is that Bin Laden's disciples would like nothing better than to avenge his death by another attack in New York."

Beginning in the early hours Monday, the NYPD, Port Authority and other agencies beefed up security throughout the city. Cops on the midnight shift worked late to provide additional protection, more bag checks were conducted in the subways and heavily armed officers fanned out to high-profile locations like Times Square and Lower Manhattan. Helicopters flew over key sites, and bridges and ferries were given extra attention.

Fire Commissioner Salvatore Cassano said the Fire Department, which lost 343 members on Sept. 11, was on alert. But a spokesman said FDNY had not yet deployed additional members.

Gov. Andrew Cuomo noted in a morning press conference that New Yorkers will see "an increased presence of personnel" at key points. He offered a reminder that "the war against terrorism goes on. The threat of al Qaeda did not die yesterday."

Residents of Lower Manhattan noticed extra police officers on the street. Julie Menin, the chairwoman of the local Community Board, said she had seen "a very significant NYPD presence all throughout Ground Zero." She said residents of the area she had talked to felt a "sense of justice," but also some concern about the potential for retaliatory attacks.

Indeed, CIA Director Leon Panetta warned, "The terrorists almost certainly will attempt to avenge him."

Rand Corporation Special Adviser Brian Jenkins, a former Green Beret and advisor to the National Commission on Terrorism, said he thought al Qaeda might aim for "a dramatic response." And he said intelligence over the years shows "New York is their favorite target."

But he added that beyond potential "spontaneous acts of violence," al Qaeda is not an organization with "a large army in reserve" ready to attack the city. Still, he said it was possible that bin Laden's death could inspire some to "emulate" him, "to perhaps take risks they wouldn't before."

"We have to be ready for increased threats of attack," Rep. Peter King (R-N.Y.), the chairman of the House Homeland Security Committee, told HuffPost. "There's no doubt about it -- they are going to want to avenge this."

But King said al Qaeda would lack the element of surprise in any potential attack. "Our intelligence people, the police, the FBI, the JTTF [Joint Terrorism Task Force] -- they're mobilized, they're ready to do what has to be done," he said.

State and city elected officials' comments reflected those of Homeland Security Secretary Janet Napolitano, who said Monday that while there were no plans to raise the terror alert level, federal agencies remained in a "heightened state of vigilance."

The U.S. Parks Department confirmed that there would be increased security around sites like the Statue of Liberty and Ellis Island. Captain Greg Norman of the U.S. Park Police said his organization had adopted a "responsive" strategy to possible threats, explaining, "We fluctuate security [measures] based on intelligence."

For the most part, local religious organizations in New York City were cognizant of potential security threats, though few were putting any additional protective measures in place. A representative from the Fifth Avenue Synagogue explained that the building has been on alert since the Sept. 11 attacks, noting that there were metal detectors and bag checks in place. But she dismissed any further precautions, saying the synagogue was already taking "maximum" security measures.

Imam Omar Saleem Abu-Namous of the Islamic Cultural Center of New York noted that he was "relieved" at the announcement of bin Laden's death, and said he did not think there would be any retaliation against Muslims living and worshiping in the U.S.

While he offered that "It's wise to have extra security," he noted that there were no new measures being put in place at the center's mosque. "I don't think anything will happen," he said. "I don't think there will be any violent [civilian] reactions to this -- not even in the Middle East."

Video by HuffPost's Hunter Stuart