Service on some GO Transit bus routes to and from Union Station has resumed after a collision forced the bus terminal to shut down for more than four hours.

Routes 31 Georgetown, 61 Richmond Hill, 63 King City, 65 Newmarket, 71 Stouffvile resumed service at approximately 7 p.m. on Monday.

Metrolinx officials said the busy downtown bus terminal was shut down as a result of a crash that occurred shortly before 2:30 p.m.

A GO bus entering the station stopped and dropped off passengers; it then accelerated into the terminal building, causing significant damage.

Officials determined that the structural integrity of the building was not compromised, but the station was without power for several hours.

Passengers on buses coming into Union Station disembarked at an alternate site. Those who were planning on taking a GO bus from the station were accommodated on trains, as the Union GO train terminal were still operational.

The cause of the accident is not immediately clear.

No one was hurt during the incident.

With a report from Scott Lightfoot