A submarine that made history with a trip the bottom of the Mariana Trench was laid low this week on a Connecticut highway.

The sub, the DEEPSEA CHALLENGER , was damaged by a fire on a flatbed truck while in transit early Thursday. The submarine made history in 2012, when filmmaker and explorer James Cameron became the first person to pilot a vessel solo to the bottom of the Challenger Deep in the Pacific Ocean's Mariana Trench, the deepest place on the planet, at 35,787 feet (almost 11,000 meters).

“We don't know the full extent of the damage yet, but what I do know is that the sub is built tough, and the section that burned is mostly buoyancy, with no critical systems,” James Cameron said in a statement.

“The pilot sphere, the hydraulics, the thrusters, robotic arm and the other complex and expensive systems are safe,” said Cameron, a National Geographic explorer-in-residence known for directing such films as The Abyss, Avatar, and Titanic. “So, in my mind it's a certainty that DEEPSEA CHALLENGER can dive again."

The submarine, which is still the deepest diving manned sub in the world. caught fire on Interstate 95 in the town of North Stonington around 5 a.m. ET Thursday. Investigators are still determining the cause of the blaze.

North Stonington Fire Marshal George Brennan says the most likely cause of the fire was a failure in the truck’s brakes, which then ignited the rear tires, followed by the submarine. It’s possible a tire went flat and ignited first, but preliminary work suggests the brakes.

On the scene, Brennan had suggested the sub may have suffered a total loss, fueling speculation about its future.

“I’m not a marine expert, but I would not want to be the first one to go down in it if they get it repaired,” says Brennan, who added that there's a noticeable hole in part of the vessel. “It’s not unusual for trucks to catch on fire, but when a dispatcher called me and told me we had a submarine on fire on the highway, I couldn’t believe it.”

Learn more about the sub's historic dive.

Cameron donated the submersible to the Woods Hole Oceanographic Institution, the world's largest private, non-profit oceanographic research institution, on the one-year anniversary of his historic dive in 2013. It was in transit from Woods Hole, Massachusetts, to Baltimore, Maryland, where it was to be shipped to Australia on temporary loan.

In addition to being the only person to visit the Challenger Deep alone, Cameron was the first to explore it in depth . He collected scientific data on the geology and life there before resurfacing 70 minutes later about 300 miles (500 kilometers) southwest of Guam.

"There are always setbacks in exploration,” Cameron said in the Friday statement. “That's how I see this--a setback.”

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