The eight-hour SkyTrain shutdown yesterday was an accident caused by a piece of replacement rail that fell in front of a train, TransLink says.

SkyTrain stopped running in downtown Vancouver at around 2:30 p.m. PT Tuesday afternoon, leaving commuters stranded and delayed between Waterfront and the Commercial-Broadway station.

It took three hours to find the broken piece, hidden behind a short wall next to a track near Science World, said Richard Sykes, maintenance vice president for TransLink.

"We dispatched two teams from Main Street and from Waterfront and they had to walk the entire guideway looking for the offending device," he said.

Once it was found, it took the team another five hours to make repairs, in part because crews were working in a confined space, said Sykes.

The fallen rail caused such a massive shutdown because it came in contact with a "collector shoe" on the train, said Sykes. That's a piece that collects electrical power to propel the train along the track.

The rail had been stored where it was supposed to be, but was dislodged by track vibration throughout the day, said Sykes.

Before explaining what caused the shutdown, Sykes first apologized to commuters for the disruption.

TransLink says it has no plans to refund fares or offer a free pass to commuters affected by the shutdown.