The TTC is reviewing safety protocols after learning passengers were escorted off a subway through a tunnel while a third rail carrying dangerous levels of power was live.

"The protocol exists. The problem is it wasn't followed, and so that's human error and we need to look at our processes," said Brad Ross, a spokesman for the TTC.

On Monday, passengers waited for more than an hour in a subway train stuck without power near Museum station after a situation at a nearby station had a domino effect. Eventually, the passengers were forced to disembark the train and walk along the tracks toward the station under the supervision of TTC employees.

While the passengers moved through the tunnel, a third rail was turned back on.

"It is a little bit concerning that there wasn't someone who was making sure that the power was off while we were there at track level," said Kathleen Schofield, who filmed a video of the passengers walking through the tunnel.

That third rail carries 600 volts of electricity. The TTC says its staff are trained to always treat it as though its live — even when the power is off.

The TTC says no one was in danger because passengers were escorted along a catwalk and were not near the third rail.

"My first reaction was, 'oh my God, like that's dangerous,'" said Justin Tetreault. "But when I thought about it for, you know, 10 seconds, I realized how orderly it was and that really we were in no danger."

The TTC said it has taken action against the person responsible for turning the power back on, but did not elaborate on what the action entailed.