LAC-MEGANTIC, Quebec —
Transportation Safety Board investigator Donald Ross said the locomotive's black box has been recovered but cautioned that the investigation was still in its early stages.
The tanker cars involved in the crash were the DOT-111 type — a staple of the American freight rail fleet whose flaws have been noted as far back as a 1991 safety study. Experts say its steel shell is so thin that it is prone to puncture in an accident.
The derailment also raised questions about the safety of Canada's growing practice of transporting oil by train, and is sure to support the case for a proposed oil pipeline running from Canada across the U.S. — a project that Canadian officials badly want.
Efforts continued Tuesday to stop waves of crude oil spilled in the disaster from reaching the St. Lawrence River, the backbone of the province's water supply. Environment Minister Yves-Francois Blanchet said the chances were "very slim."
Lac-Megantic's mayor said about 1,200 residents were being allowed to return to their homes.
A sense of mourning had set in among the survivors.
"Everybody that is gone — we're a close-knit community — they are my friends' children, they're former workmates, they're elderly people that I know, I knew them all," Fluet said. "I'm on adrenaline and not doing too badly, but I know that when the names come out and the funerals take place it will be another shock."