The Next Page: Terror on Knoxville 4236 trolley

Dec. 24 marked the 100th anniversary of one of the most tragic transit accidents in Pittsburgh history. On Christmas Eve 1917 at 3:18 p.m, the Knoxville 4236 trolley, crowded with more than 120 people, crashed onto West Carson Street when the motorman lost control of the car as it descended the steep grade through the Mount Washington tunnel.