LAC-MEGANTIC, Quebec — Street lights melted and heavy rail lines buckled into a 5-foot arch after the explosion of a runaway train in the little Quebec town of Lac-Megantic, where police on Tuesday gave outsiders a first, closely monitored look at the edges of the devastation.

“Go in, listen, be silent and understand, and explain to the world what happened here,” Quebec police Lt. Michel Brunet told a small group of journalists who have been reporting on the disaster, which killed 50 people and destroyed the center of this lakeside town near the Maine border.

The epicenter of the blast, the “red zone” of about half a square mile, is still considered too dangerous for all but investigators and emergency workers.

But even from just outside that central core, the scale of the destruction is clear, with burned-down buildings, mountains of rail-related debris and charred, black, leafless trees.

The crash happened early in the morning of July 6, when a runaway train hauling 72 tanker cars of crude oil smashed into the town’s center, derailed and exploded into vast fireballs.

Some 37 bodies have so far been recovered and there is no hope that any of those still missing will be found alive after the disaster, which highlighted the risks of moving oil by rail, an increasingly popular option for energy producers that are unable to find space on crowded pipelines to refineries.

Close to where the train went off the rails, investigators climbed atop a twisted pile of metal wheelsets, the axle-wheel combination that holds a rail car on the tracks, to look at some of the tankers, which are jumbled in a three-story heap above ground that has sagged under their weight.

The investigators work in shifts of 15 minutes at most, hampered by high temperatures and the pervasive smell of fuel.

Many of the cars are burned black from the smoke and flames, and oil has leaked into the area and into Lac- Megantic itself, a deep blue body of water that stretches south from the town.

Rocks on the waterfront look like gigantic pieces of charcoal, burned mostly black, with white splotches from ash.

“It will take years, years. We won’t get our beautiful downtown back anytime soon,” said Yannick Gagne, owner of the popular Musi-Cafe, where many of the dead were partying as the train roared into town.

Gagne and another resident, Guy Ouellet, have launched a class action lawsuit to win compensation for the small community. Ouellet lost his partner, Diane Bizier, in the explosion.

The motion to bring a class action suit, to be filed in the district of Saint-Francois in southeastern Quebec, seeks compensation for those who have lost loved ones or were injured in the explosions. It also includes claims for property or business losses.

Montreal, Maine and Atlantic Railway Chairman Edward Burkhardt and railway President Robert Grindrod are named in the document, along with numerous other company executives, as is Thomas Harding, who was the train’s engineer.

Police allowed the one-time trip into the disaster zone after multiple media requests and after consultations with locals in the picturesque town. It will likely take weeks before outsiders are allowed into the center of the disaster zone.

Burkhardt said last week he believed the train’s hand brakes had not been set properly when it was parked for the night uphill from Lac-Megantic. He singled out the train’s one-man crew, Harding.

Harding’s attorney, Thomas Walsh, described those comments as “very premature” and said the various investigations into the disaster should be allowed to do their work.

Walsh said Harding is a witness rather than a suspect in the investigation of the disaster, and is devastated by what happened.

“Since he [Harding] was more closely involved as the conductor, the person who’s responsible for the train, obviously he’s very, very affected. … He’s devastated by it,” Walsh told Reuters on Tuesday.

Quebec police have said their investigation of the crash is still in its early stages, although they say criminal negligence is a possibility they are looking at. The center of Lac-Megantic is considered a crime scene.

Canada’s Transportation Safety Board has also opened an investigation into the crash, focusing in part on the number of hand brakes that were set on the train, which had been parked for the night on a part of the main line some 8 miles from town.

Safety board officials have said an accident of this kind is never the fault of a single factor or a single individual.