After Toronto firefighters determined that nothing was ablaze, TTC crews repaired the smoking train car, transit commission spokesman Brad Ross said. "But when power was restored [to the train], a communications cable at Runnymede Station arced and smoked, knocking out communications," a press release said. The TTC could not operate until radio communications were restored, something that TTC crews worked on overnight, Ross said. But Ross said investigators suspect it happened as a result of a faulty power cable beneath the westbound train car in question. The TTC shutdown that snarled Thursday's afternoon commute came down to a smoking subway car that set off a chain reaction, cutting out communications for hours at Runnymede Station, transit officials say.

Source: CBC News May 20, 2016 11:00 UTC