A freight train derailed in Etobicoke Friday afternoon, blocking several rail lines and halted almost all Go Train service during the evening rush-hour.

A loud screeching sound was heard by residents of Manchester Street moments before six empty tanker cars went off the tracks near Mimico rail station Friday afternoon.

"First I thought maybe it wasn't going that fast," resident Joey Deonannan said. "And I seen (sic.) one of those black tanker cars with the back end dragging along the tracks and I watched the rest of then just start falling."

The train had a total of 129 cars at the time of the accident. CN Rail said most of the cars on the westbound train were empty.

The rail cars that jumped the track were:

• Three empty tank cars which last contained corn syrup, or a similar substance;
• Three empty gondola cars; and
• One empty multi-level auto carrier car

There were no injuries and no hazardous materials were spilled in the accident.

"Nothing leaking, nothing hazardous, so that's a good thing and the main thing that no one has been hurt," city councillor Mark Grimes said.

CN Rail investigators were sent to the accident site within an hour of the train jumping the tracks, company spokesperson Ian Thomson said. A reason for the derailment is not yet known.

"The crew reported that the train went into emergency, which means a brake line broke or separated, which caused the train to stop and they're now in the process of making that detailed analysis of what happened," Thomson told CTV.ca.

Thomson added it is unclear when the tracks will be cleared or if trains can be rerouted around the site.

"Once we get our equipment down there we'll be able to work pretty quickly."

Click here to see a Google Map of the area

While CN crews assessed the situation "virtually all" train traffic was halted, according to GO Transit spokesperson Edmund Shea. The result was commuter chaos at Union Station during Friday evening's rush-hour.

"There's a lot of juggling involved," Shea told CTV.ca. "Whenever something like this happens, it depends where it happens, when it happens, what trains are where."

"Even if we got the okay right now ... it will take hours to restore service because you've got to slowly bring things back to normal."

By 6:30 p.m. GO Transit announced that "limited service" had resumed on all lines. The company's website said Lakeshore west trains would not be able to stop at the Mimico station.

The company also advised customers to expect delays and possible cancellations.

With files from The Canadian Press