What to Know
10 people were killed when a van plowed into pedestrians in Toronto
Hours later, 15 people remained hospitalized
A 25-year-old was arrested as the suspected van driver
Police in Canada's biggest city are piecing together witness accounts and surveillance video trying to determine why a driver plowed a rented van along a crowded sidewalk, killing 10 people and injuring 15 in what many said seemed a deliberate attack.
A 25-year-old suspect was quickly captured in a tense but brief confrontation with officers a few blocks away from where his van jumped the sidewalk Monday and continued for a mile, leaving people bloodied and dead in his wake. But authorities so far had not disclosed a possible motive or cause even as the police chief agreed with witnesses that it seemed intentional.
"The incident definitely looked deliberate," Police Chief Mark Saunders told reporters at a late-night news conference.
Saunders said the suspect, Alek Minassian, who lives in the Toronto suburb of Richmond Hill, had not been known to police previously. An online social media profile described him as a college student.
Officials would not comment on a possible motive except to play down a possible connection to terrorism, a thought that occurred to many following a series of attacks involving trucks and pedestrians in Europe and the presence in Toronto this week of Cabinet ministers from the G7 nations.
Asked if there was any evidence of a connection to international terrorism, the chief said only, "Based on what we have there's nothing that has it to compromise the national security at this time."
But a senior national government official said earlier that authorities had not turned over the investigation to the Royal Canadian Mounted Police, a sign that investigators believed it unlikely terrorism was the motive. The official agreed to reveal that information only if not quoted by name.
Mental illness is the leading theory for a motive, several American and Canadian law enforcement officials briefed on the investigation told NBC News. And while it appears that the suspect acted deliberately, terrorism does not seem to have been his motive, U.S. law enforcement officials said.
Authorities released few details in the case, saying the investigation was still underway, with witnesses being interviewed and surveillance video being examined.
"I can assure the public all our available resources have been brought in to investigate this tragic situation," Toronto Police Services Deputy Chief Peter Yuen said earlier.
Police said the suspect was scheduled to appear in court at 10 a.m. Tuesday, and that information on the charges against him would be released at that time.
The incident occurred as Cabinet ministers from the major industrial countries were gathered in Canada to discuss a range of international issues in the run-up to the G7 meeting near Quebec City in June. Canadian Public Safety Minister Ralph Goodale called the incident a "horrific attack" and said the G7 foreign ministers extended their condolences.
The driver was heading south on busy Yonge Street around 1:30 p.m. and the streets were crowded with people enjoying an unseasonably warm day when the van jumped onto the sidewalk.
Ali Shaker, who was driving near the van at the time, told Canadian broadcast outlet CP24 that the driver appeared to be moving deliberately through the crowd at more than 30 mph.
"He just went on the sidewalk," a distraught Shaker said. "He just started hitting everybody, man. He hit every single person on the sidewalk. Anybody in his way he would hit."
Witness Peter Kang told CTV News that the driver did not seem to make any effort to stop.
"If it was an accident he would have stopped," Kang said. "But the person just went through the sidewalk. He could have stopped."
Video broadcast on several Canadian outlets showed police arresting the driver, dressed in dark clothes, after officers surrounded him and his rental Ryder van several blocks from where the incident occurred in the North York neighborhood of northern Toronto. He appeared to make some sort of gesture at the police with an object in his hand just before they ordered him to lie down on the ground and took him away.
Witness Phil Zullo told Canadian Press that he saw police arresting the suspect and people "strewn all over the road" where the incident occurred.
"I must have seen about five, six people being resuscitated by bystanders and by ambulance drivers," Zullo said. "It was awful. Brutal."
Police shut down the Yonge and Finch intersection following the incident and Toronto's transit agency said it had suspended service on the subway line running through the area.
Prime Minister Justin Trudeau expressed his sympathies for those involved. "We should all feel safe walking in our cities and communities," he said. "We are monitoring this situation closely, and will continue working with our law enforcement partners around the country to ensure the safety and security of all Canadians."
The U.S. stands with the Canadian people "in the aftermath of today's tragic event in Toronto," White House press secretary Sarah Huckabee Sanders said in a statement Monday night.
"Our thoughts and prayers go out to the families of those affected, and we wish a full recovery to those injured. The United States Government pledges to provide any support Canada may need," she said.