WASHINGTON - Federal regulators have opened an investigation into 3 million Jeep Grand Cherokees to determine whether more than a dozen post-crash fires and deaths are connected to the placement of the SUV's fuel tank, reported Automotive News.

The National Highway Traffic Safety Administration said today its preliminary examination of 1993-2004 Jeep models found 13 deaths in 10 crashes “most likely associated with the alleged defect.”

The nonprofit Center for Auto Safety alleges the Grand Cherokee features a fuel tank that extends below the rear bumper, behind the rear axle, and lacks adequate protection in crashes and rollovers. The tank's fuel filler neck also tears off in crashes, the group contends in a petition to the federal agency.

NHTSA also found complaints from vehicle owners alleging nine injuries and one death stemming from post-crash fuel tank leaks or fires, the agency said on its Web site.

Chrysler Group said it is cooperating with the investigation.

“It is important to note that this is an investigation, not a recall,” Chrysler spokesman Michael Palese said. “Indeed, the 1993-2004 Jeep Grand Cherokee meets or exceeds all applicable federal safety standards and has an excellent safety record.”

The company said in a statement last November that it “is confident that a study which considered all factors in all collisions -- including rear collisions with fire -- would show that the 1993-2004 Jeep Grand Cherokees perform as well as or better than other vehicles in their class.”

Chrysler still stands by that statement, Palese said today.

But Clarence Ditlow, head of the Center for Auto Safety, called on Chrysler to recall all 1993-2004 Jeep Grand Cherokees.

"More people have burned to death in fatal fire crashes than in the infamous Ford Pinto," he said in a prepared statement.

NHTSA said consumer complaints of post-crash fires do not by themselves “establish a defect trend.”

In addition, NHTSA's preliminary review of early warning reporting data on the Jeep Grand Cherokees “did not find the subject vehicles to be over-represented for post-crash fires.”

In one case that led to a settlement with DaimlerChrysler, Chrysler's former owner, Kenneth Smith of Jacksonville, Fla., was driving his 1995 Jeep Grand Cherokee through an intersection when it was rear-ended by a Lincoln Town Car going 20-25 miles an hour, according to a statement by Smith's attorney.

“Immediately upon impact, the Jeep burst into flames,” the 2002 statement said. Smith “suffered burns to his abdomen, right hand and arm. He has undergone two skin grafts, and must wear special garments to protect his arm and hand,” the lawyer said.

The Center for Auto Safety, which was founded by Ralph Nader, filed a petition in October 2009 that cited NHTSA's own files that show the vehicles at issue were involved in 172 fire crashes leading to 254 deaths from 1992 to 2008.

The 1993-2004 Jeep Grand Cherokee has a fatal-crash-with-fire rate that is quadruple that of SUVs made by other companies, the petition contends.

When DaimlerChrysler owned the Jeep brand, it moved the Grand Cherokee's fuel tank beginning with 2005 models and shielded it, the petition said. Since that change, only one crash resulting in a fatal fire has occurred.

The petition cited a couple of lawsuits in which many details are not available because of confidential settlements

In one case, a stopped 1997 Grand Cherokee was struck from behind in Long Island, N.Y., by a braking Toyota MR2.

The driver of the MR2, a gardener, was fatally burned when he was enveloped by burning fuel from the ruptured tank of the Grand Cherokee, the petition alleged.

Two sisters in the back seat of the Grand Cherokee were severely burned when they could not get out because the doors jammed, according to the petition.

The crash shows “the unique hazards of an unshielded tank extending below the rear bumper,” the petition said.