A young woman died Monday morning hours after she was hit by a truck on the Gardiner Expressway.

Investigators are trying to determine how 19-year-old Katie Traverso ended up on the eastbound lanes of the highway, near Jameson Avenue, around 2:30 a.m. Police believe she was a passenger in an eastbound Toyota Corolla but don’t know if she jumped, or was thrown from the vehicle.

The accident prompted an hours-long closure on the Gardiner. Police shut the eastbound lanes down between Jameson and Spadina for five and a half hours.

Police say a 23-year-old woman was driving the Corolla. 

A 40-year-old man was driving the truck.

There’s no word if charges will be laid.