AMSTERDAM — The man who drove his car into a crowd of parade spectators and killed six people died of his injuries Friday, leaving unresolved the mystery of why he tried to attack the Dutch royal family.
The 38-year-old suspect, identified by Dutch media as Karst Tates, had been in critical condition since the attack Thursday on Queen's Day, the Dutch national holiday.
Hours after his death during the night, the Defense Ministry announced that a 55-year-old driver for the military police, Roel Nijenhuis, also died of his injuries. Five bystanders died on Thursday.
Nijenhuis was on duty during Thursday's parade, said a statement from the service commander, Lt. Gen. Dick van Putten. He had driven a military police band to the parade and was watching the festivities when he was hit.
Ten other people were hurt when the man rammed his small black car through police barricades toward an open-topped bus carrying Queen Beatrix and several other members of the royal family.
He told one of the first police officers to rush to his car that the attack was aimed at the royal family, prosecutor Ludo Goossens said Thursday. But the motive was unclear.
"It is very difficult now that we no longer have the suspect to reconstruct what was behind this," said Fred de Graaf, they mayor of Apeldoorn where the incident occurred.
"An element of uncertainty will remain because you can no longer question the suspect. So the last piece of the puzzle will remain in question," he told reporters Friday.
Dutch media, citing neighbors, said Tates recently was fired from his job as a security guard and was to be evicted from his home in the small eastern town of Huissen because he could no longer afford the rent. Police said he had no history of mental illness or police record.
The neighbors described him as friendly, but a man who kept to himself, the NRC Handelsblad reported.
Prosecutors said the suspect's death ended the criminal investigation against him, but that they would continue to investigate whether he acted alone. Prosecutors have not released his name, in line with Dutch privacy laws.
"So far there are no indications" anybody else was involved, prosecutors said in a statement.
Police who searched the man's house Thursday "found no weapons, explosives or indications of other suspects," prosecutors said. No links with terrorism or ideological groups were immediately uncovered, they said.
The attack prompted officials to review security arrangements for the royal family's public appearances, beginning with Memorial Day next Monday commemorating Dutch victims of World War II, followed Tuesday by Liberation Day festivities. The state broadcaster NOS said the 71-year-old monarch would attend at least the main memorial ceremony as planned.
The queen and her son Crown Prince Willem-Alexander seldom hesitate to approach the crowds on holidays, especially on Queen's Day, when the members of the House of Orange are the focus of attention.
Now, the attack raised questions about "whether Queen's Day can ever again be celebrated in the way we Dutch are accustomed to _ with as its most important feature the closeness of the queen, her family and the Dutch public," said De Volkskrant daily.
De Graaf defended security during Thursday's parade. "You don't assume somebody will drive straight through a crowd, straight through two barriers to do something like this. You don't plan based on that kind of scenario," he said.
On Friday, people laid bouquets of flowers at the scene of the attack, lit candles in Apeldoorn's church and signed a condolence register at Apeldoorn city hall for the victims.
The failed attack on the immensely popular royal family played out live on nationwide television during coverage of the queen's bus trip to her palace Het Loo in the eastern city of Apeldoorn.
Friday newspapers and Web sites featured photos of the carnage wreaked by his small black car as it plowed through crowds of people hoping to catch a glimpse of the royals.
The car came to a halt when it slammed into a stone monument just yards (meters) from the royal bus.
A shaken Queen Beatrix extended her sympathies to the victims in a brief nationally televised address Thursday. "What began as a great day has ended in a terrible tragedy that has shocked us all deeply," she said.
Officials in Apeldoorn said he had a map of the queen's route.
Eight victims remained hospitalized Friday, including two children, the Apeldoorn mayor said. One woman was still in critical condition.
Officials had said that in addition to the dead, 12 people had been injured, but on Friday said the driver had been counted among them.
Celebrations were canceled for Queen's Day, the national holiday that draws millions of people to street dances, picnics and outdoor parties around the country. Flags were lowered to half staff.
Associated Press reporter Mike Corder in The Hague contributed to this report.