Windsor, Ont. — Investigators say a man apparently stabbed himself, set himself on fire and then “intentionally” crashed a burning truck into a Children's Aid Society building on Tuesday.

The blazing pickup slammed into the front of the newly built facility just an hour before children and their families usually arrive at the centre.

“Oh, this was intentional,” said Staff Sgt. Gerry Corriveau after surveying the wreckage. “He was trying to blow up the building.”

Police and fire officials said the driver and his blue Ford pickup were already in flames when the truck smashed into the four-storey building's north facade around 7:30 a.m. causing $1.5 million in damage.

“The truck was on fire prior to its impact,” Staff Sgt. Corriveau said. “In fact, the driver was on fire as well.”

Nobody was hurt other than the driver, who was badly burned and is listed in critical condition.

Staff Sgt. Corriveau said only six employees were inside at the time of the crash.

After lining the truck's bed with aerosol spray cans and two gasoline cans, the 49-year-old driver lit a pair of propane tanks inside the truck's cab, police said.

He then sped toward the glass-walled building, but the truck didn't explode on impact.

The man suffered second-degree burns to 20 per cent of his body. He also stabbed himself at some point during the ordeal, said the head of the Windsor police arson unit.

“He's got what appears to be a self-inflicted stab wound to the side,” said Staff Sgt. Stefan Kowal.

Police had yet to locate the knife as they were waiting for a warrant to search the truck's interior, Staff Sgt. Kowal said.

Staff Sgt. Corriveau said police had “some indication that the person involved was an ex-employee of the Children's Aid Society.”

Local CAS executive director Bill Bevan would not divulge the man's name, but said he worked well with youngsters, with whom he sometimes lived in CAS-rented apartments.

“This person was a well-respected employee,” said Mr. Bevan, who did not know what prompted incident. “We don't have any early guesses around that. Let's hope the individual survives, and they can tell their story and we can find out why they would ever think to do this.”