Service on the Lakeshore West GO line was disrupted for several hours on Tuesday afternoon after a collision at a crossing near Lakeshore Boulevard and Cawthra Road.
Authorities say early indications are the driver of a car was heading south on a residential street when he clipped the back end of a GO Train locomotive.
The force of the impact tore the front end off of the car and scattered debris down the tracks for metres.
Officials say the train sustained minor damage.
Incredibly, the driver was able to climb out of the wreckage and was seen by witnesses staggering around the tracks until emergency crews showed up.
The man was taken to hospital as a precaution.
The investigation continues.