On September 17, 2007, while pulling south on the pullback track with consist of 67 loads and 30 empties, weighing about 9054 tons, the 2200 West yard assignment side-collided with the tail end of train M33931-17. The train was departing MacMillan Yard at 15 miles per hour on the Halton outbound track. Two locomotives and two cars of the yard assignment derailed. Six cars on train 339 derailed and/or sustained damage, including two special dangerous goods tank cars containing chlorine (UN1017). Approximately 3785 litres of diesel fuel (UN1202) leaked from the derailed locomotives. There were no injuries. On July 29, 2015, 91 freight cars ran away in the yard after they separated from a switching locomotive. Nine of those freight cars derailed and two freight cars on an adjacent track were damaged when the runaway cars collided at low speed with other cars that were a part of an incoming train in the yard. No injuries were reported. The
Transportation Safety Board sent two inspectors to the site to investigate the incident. On June 17, 2016, a runaway train incident occurred at the yard, in which 74 rail cars — one of them carrying dangerous goods — rolled away uncontrolled for five kilometres, continuing outside the yard onto the mainline. The TSB said that ground crews were using a remote control device known widely in the industry as a "belt pack" to assemble a train when the 72 loaded cars as well as two empty ones rolled away uncontrolled. On May 12, 2017, a derailment caused a chemical spill. At around 11:30 p.m. ET, a locomotive derailed and "sideswiped" seven hopper cars. The impact resulted in a spill of a powdered form of
terephthalic acid, a compound used in the manufacturing of plastics. On August 15, 2019, another derailment caused the death of a worker. At around 2 a.m. ET, emergency services were called. They found a CN worker trapped beneath a rail car that had derailed and fallen on its side. The employee died as a result of injuries sustained in the incident. ==References==