A city bus crashed into a day care center north of Montreal today, killing two children and injuring six, authorities said. The driver was arrested and charged with homicide and careless driving.

A neighbor who ran to the center in Laval, Quebec, said she saw children screaming and crying and watched a mother collapse. Other panicked parents were diverted to a nearby elementary school as dozens of police and emergency vehicles swarmed the area.

Immediately after the crash, the driver stepped out of the bus, ripped his clothes off and started screaming, another neighbor said.

“He was just yelling; there were no words coming out of his mouth,” Hamdi Benchaabane said. The driver, he said, “was in a different world.”

The driver is 51, had worked for Societe de transport de Laval for 10 years, and had no criminal history and a clean work record, police officials and Laval Mayor Stéphane Boyer said at two separate news conferences.

“As of now, we don’t know the motive for the crime,” Police spokesperson Erika Landry said. She did not say why police determined the crash to be a homicide and didn’t release the driver’s name. Laval Police Chief Pierre Brochet said police are interviewing the driver.

“There is a theory that it was an intentional act, but that remains to be confirmed by the investigation,” Boyer said.

The day care is located at the end of a driveway off a cul-de-sac. There is a bus stop on the cul-de-sac, but the driver would have had to veer off the road and head down the long driveway to hit the building.

“There were no signs of skidmarks. …. He went directly into the day care,” said another eyewitness, Mario Sirois.

Sirois’ wife, Ginette Lamoureux, the neighbor who ran into the day care shortly after the crash, said the driver was hysterical.

“His eyes were like popping out,” she said.

The six children who were hospitalized had injuries that were not life-threatening, Brochet said.

A senior Canadian government official said the crash was not a terrorist act and did not pose a threat to national security. The official spoke on condition of anonymity as they were not authorized to speak publicly on the matter.

Benchaabane said he and three parents had to strike the driver in order to subdue him, before police cuffed him.

Brochet said officers at the scene were crying.

Prime Minister Justin Trudeau said his office was “following the situation closely.”

Members of Parliament observed a moment of silence in Ottawa.