The National Highway Traffic Safety Administration (NHTSA) has launched an investigation into a possible defect with the gas tanks on 1993-2004 Jeep Grand Cherokees. The investigation was encouraged by the advocacy group Center for Auto Safety in October when they said that the plastic fuel tank was susceptible to ruptures during rear end collisions and roll overs.

In the last two decades, the NHTSA said that there have been 55 deaths in crashes involving the sport utility, in which fire was listed as the probable cause of death. In ten of those crashes, the vehicle was involved in a rear end collision.

After an initial review, the NHTSA has reported that the Grand Cherokee does not have a significantly higher number of fires than any other vehicle. In a statement, NHTSA said, “The existence of these post-crash fires does not, by itself, establish a defect trend.” Further review and investigation into these accidents is needed to determine if the problem constitutes a recall.