But, Cooper's message was not passed on to Quebec before it was too late. Near quitting time that same afternoon, after four years of construction, the south arm and part of the central section of the bridge collapsed into the St. Lawrence River in 15 seconds. Of the 86 workers on the bridge that day, 75 were killed and the rest were injured, making it the world's worst bridge construction disaster. Of these victims, 33 (some sources say 35) were Mohawk steelworkers from the Kahnawake reserve near Montreal; they were buried at Kahnawake under crosses made of steel beams.