An investigator who declined to be identified looks over the damage to the Deepsea Challenger deep-diving submersible resting on its transport trailer in North Stonington, Conn. Thursday, July 23, 2015. The vessel was damaged by fire while being transported along I95 from Woods Hole to Baltimore. Filmmaker and ocean explorer James Cameron piloted the submersible in 2012 to a depth of nearly 35,800 feet (10,900 metres) in the deepest spot on the planet—the Mariana Trench near Guam. (Sean D. Elliot/The Day via AP)

The submarine that visited the deepest spot in the world's oceans has been scorched when a truck transporting the vessel caught fire on a Connecticut highway.

State Police responded to the Thursday fire on a truck transporting the Deepsea Challenger on Interstate 95 in North Stonington.

Filmmaker and ocean explorer James Cameron piloted the submersible in 2012 to a depth of nearly 35,800 feet in the deepest spot on the planet—the Mariana Trench near Guam.

The sub's owner, the Woods Hole Oceanographic Institution in Falmouth, Massachusetts, said in a statement that the fire caused some damage to the submarine. The extent of the damage and the fire's cause are under investigation.

The sub was to be shipped to Baltimore and then Australia on a temporary loan.