A woman tried to light herself on fire after fleeing a five-vehicle collision in north Toronto that she triggered, police say.

The woman, who was one of the drivers in the supper-hour crash Wednesday on Bayview Avenue north of Sheppard Avenue, ran almost a kilometre away from the accident scene and into a stranger's home.

The woman, who police said was in her 40s, entered the kitchen of a home on a quiet residential street and tried to use the stove's gas burners to light herself ablaze, investigators said.

The home's owner, Dorothy Badner, said went back into her house after taking the trash out and found a woman leaning over her gas stove with all of the burners on "trying to set herself on fire."

After Badner turned off the burners, the woman ran frantically back outside.

Paramedics arrived to find the woman collapsed and rushed her to hospital with non-life-threatening injuries. Toronto police said they may lay charges for failure to remain at the scene, pending the results of a psychiatric assessment.

Police said the woman triggered the collision when her white Mercedes struck another car, starting a chain reaction. Paramedics rushed a 65-year-old man to hospital with serious injuries after two-by-fours crashed through his windshield. He was still in hospital late Thursday afternoon but was expected to be OK, CBC reporter Jeff Semple said.

Investigators were perplexed about what set off the bizarre chain of events.

"All I can say right now is that this collision is more than just a normal traffic collision," Sgt. Andrew Bator told reporters Wednesday night.