1 May 2004 CPR Links Broken Wheel, 2 Deaths A tragic chain of events that caused a fatal train derailment in Whitby was sparked by a broken wheel, Neal Foot, senior vice-president of operations for Canadian Pacific Railway, said yesterday.   Pointing to a picture of a wheel that has most of its steel tread broken off, Mr. Foot said, "You can see very clearly what the cause of the accident was. What happened was that the wheel broke and fell between the rails as the tread deteriorated and the width of the wheel narrowed."   But the derailment of the CPR freight westbound from Montreal to Toronto at 7:41 p.m. on 14 Jan 2004 turned into a tragedy when the last two cars of the 1 1/2 kilometre-long train came crashing down an embankment onto a 2001 Oldsmobile Alero, killing Kathleen Kellachan, 36, and her niece, Christine Harrington, a 19-year-old mother.   On Thursday, officials from CPR met with Whitby Mayor M. L. Brunelle and town councillors and with the Harrington family to explain the initial findings from the rail company's investigation of the crash.   Moira Harrington, Ms. Kellachan's sister, did not return phone calls.   The rail company has also sent information bulletins to 6,000 Whitby households explaining its safety practices and how it has rebuilt the line where the accident occurred.   Both the Transportation Safety Board and Transport Canada are continuing their investigation of the crash. Mr. Foot said that "the internal investigation is complete."   He said that it showed that the rail cars did not, as was widely reported soon after the crash, fall off a rail bridge onto the road below.   He added that a study of the bridge by both the rail company and an independent engineering firm showed that it remained structurally sound after the accident.   Rather, when the wheel broke on the third car from the end of the train, which was travelling at 82 kilometres an hour at the time of the accident, it fell off the rail about 100 metres east of the bridge.   That caused the rail to break, and with no line to roll on, the last two cars on the train came off the track, their emergency brakes came on, they broke away from the train and plunged down an embankment and into the road.   "One of the cars that derailed kind of trailed across the edge of the bridge and hung out there and took the handrail off the bridge and did a few little cosmetic damages, but the cause of the derailment was the broken wheel," Mr. Foot said.   "Our investigation proved that the train crew was unaware of what was occurring with their train. They had no way of detecting the broken wheel. It was a fairly rapid deterioration."   Because the wheel broke at the rim and deteriorated very rapidly, the sensors that the railway places along its line to detect overheating of axles and wheel hubs would not have detected the wheel break, he said.   Mr. Foot also stressed that the break causing the derailment was a very unusual event. While there are about 500,000 wheels running on a CPR line every day, there are only three to four derailments a year as a result of a broken wheel.   He also noted that the Transportation Safety Board has the wheel set, but has not done the metallurgical analysis to find out why it failed.   "We know the wheel broke. We don't know why the wheel broke. And we won't know that until the Transportation Safety Board determines that."   Anatomy of tragedy   A wheel breaks on the third car from the rear of a 40-car, 1 1/2 kilometre-long freight train travelling through Whitby on its way to Toronto at 7:41 p.m., 14 Jan 2004.   The break occurs 100 metres east of a bridge over Garden Street.   The car comes off the tracks, ripping them up.   The last two cars of the train dig into the road bed, become separated from the rest of the train and plunge down an embankment onto the street where they hit a car, killing two people.