Wrecked oil tankers and debris from the runaway train that derailed and exploded in Lac-Megantic, Quebec, Canada in July 2013. The blast and fire killed 47 people and razed part of the small Quebec town. Photo: AFP

 A Canadian jury on Friday cleared three railway workers of criminal negligence in one of the nation's worst train disasters, which killed 47 people in Lac Megantic, Quebec in 2013.

Former Montreal, Maine & Atlantic train engineer and conductor Thomas Harding, operations manager Jean Demaitre, and railway traffic controller Richard Labrie, faced 47 counts of criminal negligence -- one for each death.

The 12-person jury struggled over nine days to reach the verdict, asking the presiding judge on several occasions for clarifications on matters of law, raising concerns they might have become deadlocked.

In addition to the casualties, some 30 buildings in Lac Megantic were completely destroyed on July 9, 2013 when a 72-car train carrying shale oil came loose in the middle of the night, rolled downhill unmanned, derailed and exploded.

More than 2,000 people had to be evacuated from the picturesque lakeside town. Firefighters needed two days to put out the raging blaze.

After the crash, Montreal, Maine & Atlantic declared bankruptcy.