The TTC says it will investigate after a passenger bus with no driver was caught on camera rolling through a Toronto bus parking area and hitting a parked vehicle.

In the video, which was posted to YouTube, an empty and dark bus rolls through the slush-filled bus bay at Bathurst Station before hitting the parked TTC truck. Upon impact, the bus' side-view mirror falls off, landing in the slushy snow.

Brad Ross, head of TTC communications, told CTV Toronto that the operator of the bus failed to apply the proper brakes on the bus, when he left the vehicle to use the washroom.

While no one was injured, and the bus sustained minor damage, Ross said he could imagine how some transit users would be shocked to see the empty bus rolling away.

"To see a bus slowly drifting away, without anybody on it, and with it dark, I can imagine it could be rather frightening for people," he told CP24.

Ross said the TTC will be investigating the incident and interviewing the bus operator.