Update (5:30 p.m): TransLink says the issue with the problem train has been resolved and that service is slowly returning to normal. Stations from Main Street to Waterfront are being re-opened. Staff are controlling crowd flow to prevent overcrowding on platforms.
TransLink says all downtown Vancouver Stations are being closed due to a problem caused by a train near Main Street-Science World Station.
At 4:51 p.m., spokeswoman Jillian Drews said all Expo Line trains are turning back at Commercial-Broadway.
Bus service is being made available for customers heading downtown.
Visit TransLink on Twitter for updates.