Updated

Three employees and the railway company involved in last summer's massive explosion of a runaway oil train that incinerated much of a small town in Quebec, killing 47 people, will face criminal negligence charges, provincial prosecutors announced late Monday.

The charges come about 10 months after more than 60 of the tankers carrying oil from North Dakota came loose in the middle of the night, sped downhill for nearly seven miles (11 kilometers) and derailed in the town of Lac-Megantic in eastern Quebec. At least five of the tankers exploded, leveling about 30 buildings, including a popular bar that was filled with revelers last July 6.

The Quebec provincial prosecutor's office said 47 counts of criminal negligence have been filed against engineer Thomas Harding, manager of train operations Jean Demaitre, and Richard Labrie, who was in charge of rail circulation, as well as the Montreal, Maine and Atlantic Railway Ltd., the defunct railway at the heart of the disaster.

Rene Verret, a spokesman for the prosecutor, said the three railway employees were placed under arrest late Monday afternoon. They are scheduled to appear in court on Tuesday in Lac-Megantic.

Quebec's director of criminal and penal prosecutions had begun a review of the file in late March. Prosecutors said in a statement that they elected to file the charges after an analysis of the evidence gathered at the scene. The railroad blamed the engineer for failing to set enough brakes, allowing the train to begin rolling toward the lakeside town of 6,000.

The MM&A railway company is in the process of being sold. In January, bankruptcy judges in Quebec and Maine approved the sale of the insolvent railway to Railroad Acquisition Holdings LLC, an affiliate of New York-based Fortress Investment Group, for $14.25 million. Fortress had the winning bid for the bankrupt railroad, which owns about 500 miles (800 kilometers) of track in Maine, Vermont and Canada.

Verret said prosecutors had hoped to announce the charges earlier, but said they had to find and arrest those charged as well as inform the families of the victims in Lac-Megantic.

A news conference is planned in Lac-Megantic on Tuesday regarding the rebuilding of the Musi-Cafe, the establishment in the heart of town where many people were killed. Mayor Colette Roy Laroche and Musi-Cafe owner Yannick Gagne are expected to attend.

The disaster prompted intense public pressure to make oil trains safer in the U.S. and Canada. Canada's transport minister said in April that the type of tankers that were involved in the Lac-Megantic disaster must be retired or retrofitted within three years because they are prone to rupturing.

The oil industry has rapidly moved to using trains to transport oil in part because of oil booms in the Bakken region in North Dakota and in the oil sands in Alberta, and because of a lack of pipelines.