A busy stretch of the TTC's Line 2 was shut down throughout the Wednesday morning rush hour, causing commuter chaos at six subway stations in the west end.

The trouble was caused by the "partial derailment" of a train that was leaving Keele Yard before morning service began, said Kadeem Griffiths, spokesperson for the TTC.

There was no service between Jane and Ossington stations for four and a half hours as crews worked to fix the issue.

Griffiths called it a "unique problem" and said most of the morning was spent trying to figure out exactly what happened.

The TTC deployed 100 shuttle buses to the closed stations but many people were left waiting for an hour or more to board one.

Passengers trying to get on at Jane and Bloor to head west. There are hundreds here waiting and when a door opens people are piling in <a href="https://twitter.com/hashtag/ttc?src=hash&ref_src=twsrc%5Etfw">#ttc</a> <a href="https://twitter.com/CBCToronto?ref_src=twsrc%5Etfw">@CBCToronto</a> <a href="https://t.co/6m3HGUXKip">pic.twitter.com/6m3HGUXKip</a> —@SannahChoi

"No matter what, shuttle buses are never going to replace the subway in terms of capacity and in terms of speeds, especially around rush hour," Griffiths said.

Hundreds of people could be seen swarming shuttle buses for a spot on board as they pulled up to Jane Station.

One single shuttle bus <a href="https://t.co/lfhjgXWDhe">pic.twitter.com/lfhjgXWDhe</a> —@Partovian

Toronto police deployed officers to help with crowd control, said Const. Victor Kwong, and even closed Bloor Street W. to traffic for a time because people were crowding into the roadway trying to catch a bus.

"I'm really frustrated with the TTC," said one riders who identified herself only as Daisy.

"This impacts peoples' livelihoods. You're going into work and you say, "Oh, I was held up by the TTC.' Nobody hears that anymore. It's like saying the dog ate my homework."

She said she struggled to figure out what was happening and where to go.

"The communication is poor. You can hardly hear what they were broadcasting, I couldn't hear what was going on," she told CBC Toronto.

"They have to do better, these delays just happen way too often."

Huge crowds of people swarmed shuttle buses outside Jane Station. (Sannah Choi/CBC)

College student Joshua Deguzman was heading to campus for the day, but after trying and failing to get onto several shuttle buses he said he might just end up heading home.

"I'm already late," he said. "Definitely going to miss most of my morning class."

Crews were able to fix the problem shortly before 10:30 a.m. (Paul Smith/CBC)

The struggles on Bloor appear to make other TTC routes busier, as well.

CBC News reporters taking both the King and Dundas routes into the downtown core reported extreme overcrowding.

The 505 bus is a nightmare this morning, send help <a href="https://t.co/KYmCYeXc9E">pic.twitter.com/KYmCYeXc9E</a> —@LaurenPelley

The King Streetcar today was basically a modern retelling Lord Of The Flies, minus the solitude of a deserted island. What was yours? —@p_evans

In a tweet issued after service resumed, said that it was a "bad morning for our customers travelling into and out of the west end and for that we apologize.

"Thankfully, subway derailments, even partial ones, are rare, but we commit to finding the root cause to avoid a repeat."

Meanwhile, TTC crews also had to scramble to pull an SUV out of the Queens Quay tunnel overnight. Somehow, a driver made it past a gate and flashing lights and over a rumble strip before lodging their vehicle against a concrete block 600 metres underground near Union Station.