Near the Maine border, a runaway train likely carrying hundreds of thousands, if not millions, of gallons of crude oil derailed Saturday and crashed into a downtown area in the Canadian town of Lac-Mégantic, Québec, causing death, destruction and untold environmental damage.

At least 40 people are missing and five are confirmed dead. A large swath of the town is destroyed and thousands were forced to evacuate.

As the community is still coming to terms with the tragedy, regional concerns over contamination to local waterways are mounting, with some reports of spilled oil in local rivers.

The news site Radio-Canada reports fears that municipal drinking water supplies may be contaminated in the community of Saint-Georges, about an hour's drive north of Lac-Mégantic.

"In the early afternoon Sunday, traces of hydrocarbons could be observed in the Chaudière River at Saint-Martin, a municipality located upstream of St. George," the news agency said in a report translated from French. A photo of a reporter holding a bottle of orange tinted river water can be seen here.

However local officials are downplaying the contamination fears. Francois Fecteau, the mayor of St. George, reportedly said the city had not detected the presence of oil in the water, but as a precaution has installed oil booms along the Chaudière River.

"We will monitor the quality of water entering our water intake to be sure that our water is consumable," he said, also noting that if oil is present it could remain there for several days or weeks.

Ten municipalities draw their drinking water directly from the Chaudière River.

All but one of the train's 73 cars was carrying oil and at least five of them exploded. The incident occurred early Saturday morning, when Lac-Mégantic's downtown bars were still full of people. It's unclear how the oil train became unparked and sped downhill out of control for nearly seven miles before derailing in downtown Lac-Mégantic, however most reports speculate that an air break on the train was unintentionally disengaged.

"The train was parked, it was tied up. The brakes were secured. Somehow it got loose," said Joe McGonigle, vice president of marketing for Montreal, Maine & Atlantic Railway, the company responsible for the train, according to the Associated Press. McGonigle called the incident "unfortunate" but said that accidents will happen no matter the mode of transportation.

Montreal, Maine & Atlantic Railway carried nearly 3 million barrels of oil across Maine last year, according to The Guardian, which reported that "each tank car holds some 30,000 gallons (113,600 liters) of oil." If the 72 oil-loaded train cars were fully filled, then 2,160,000 gallons of oil (about 51,000 barrels) were involved in the incident.

"This is an unbelievable disaster," Canadian Prime Minister Stephen Harper, said, according to the AP, which reported that lines trees in the area were charred like giant standing matchsticks, blackened from top to bottom.

"This is an enormous area, 30 buildings just completely destroyed, for all intents and purposes incinerated," Harper said. "There isn't a family that is not affected by this."