Tuesday marks the 20th anniversary of the deadliest subway crash in Toronto’s history.

On Aug. 11, 1995, three people were killed and 30 others were injured after a train rear-ended another train stopped part way between St. Clair West and Dupont stations.

More than 200 passengers were on board the trains at the time of the crash and some had to be extricated from the wreckage.

The TTC later determined that the deadly accident was caused by a combination of human and mechanical error.

In a series of tweet sent out Tuesday, TTC spokesperson Brad Ross said the transit service is marking the tragic incident by remembering the victims today.