LAC-MEGANTIC, Quebec — Insufficient brake force was applied before an oil train came barreling out of nowhere in the middle of the night and slammed into a small town in Quebec, killing 47 people, officials said Friday.
Donald Ross, chief investigator for the Transportation Safety Board of Canada, said the insufficient brake force could have been due to mechanical problems with the handbrakes, or a problem with the way someone applied them.
''The train got out of control because it wasn't fully immobilized,'' said Transportation Safety Board manager Ed Belkaloul.
An unattended Montreal, Maine & Atlantic Railway train was parked overnight on a rail line before it came loose, hurtling down a seven-mile incline.
The train derailed and ignited in Lac-Megantic, near the Maine border. All but one of its 73 cars was carrying crude oil and at least five exploded, setting off massive explosions that devastated the small lakeside town of 6,000 people.
A spokesman for the agency said it has had a closer look at 25 tanker cars since gaining access to the blast site two days ago and has taken pictures and samples.
The investigators said they are also analyzing the contents of the tanker cars that did not explode in the crash, looking for clues on why the crude oil in the other cars did so violently.
The agency says the investigation has already resulted in two safety advisories urging a revision of the Canadian Rail Operating rule governing the securing of parked trains.
It says the rule is not specific enough because it does not spell out how many handbrakes to apply for various weights and types of cargo. It also said the standard, so-called ''push-pull test'' does not always accurately show whether the brakes have been adequately applied.
The board has also advised Transport Canada that dangerous goods should not be left unattended on a main track and that rail equipment needs to be properly secured.
The transportation watchdog's advisory comes a week after Edward Burkhardt, president and CEO of the railway's US-based parent company, Rail World Inc., blamed the train's engineer for the accident. Burkhardt questioned whether he had properly set enough handbrakes and said he had been suspended without pay.
The board said that while the investigation is expected to take quite some time, it will not wait to send safety warnings.