VANCOUVER - Metro Vancouver's transit authority is warning morning commuters about crowding and delays as a fire has halted a major SkyTrain line.

TransLink has issued an advisory that says the blaze damaged a communications cable and a section of the Expo Line will be shut down between Vancouver and Burnaby as crews make repairs.

It says the fire started at about 11 p.m. last night when a spark from the track caused a bird's nest to ignite under a guideway, east of the Main Street SkyTrain station.

TransLink is advising people who take the Expo Line between Waterfront and Joyce-Collingwood station to find alternate travel arrangements.

It says crews worked through the night but repairs are not expected to be finished until the late morning or early afternoon.

TransLink says a bus shuttle will be set up between Waterfront and Joyce station, although it is warning that heavy crowds are expected on all the major routes.

Stranded commuters were quick to vent on Twitter about the transit service, upset about the delays and the cost of finding an alternate way home.

Service is not expected to be restored until late morning or early afternoon. No word on what caused the fire.