As we come on the air, rush hour is under way. 124 million americans traveling the roads and millions of people learning of a new warning about their cars. 2.7 million older jeeps, with fuel tanks... See More
As we come on the air, rush hour is under way. 124 million americans traveling the roads and millions of people learning of a new warning about their cars. 2.7 million older jeeps, with fuel tanks that reportedly can lead to gasoline fires in a rear-end collision. Tonight the government requested that chrysler issue a giant recall. Chrysler saying no. So what does this mean? Lisa stark has been investigating this issue for three years, and tonight she has the facts. Reporter: It was fiery deadly, kas like these that raised alarms. Now the government says there's a safety defect in the older model jeeps. Fuel tanks that are vulnerable to rupture in rear-end collision. We're nearing the end of people dying by fire in jeeps. Reporter: You can see in these crash tests, simulating fuel spilling from the cherokee. Chris leer claimed the tests were too severe. But today the national highway administration called on chrysler to recall all older jep grand cherokees and jeep grand liberties, saying the people in the vehicles and in striking vehicles have burned to death in rear-impact crashes. The problem, according to the government is the fuel tank location. Right behind the rear axle, and slightly below the bumper. Chrysler moved the tank in later models, it says, for design reasons. Jennel embri has been waging a campaign against the jeeps after a horrific rear-end smash up last october. A tractor trailer rammed into a jeep grand cherokee stopped in traffic. The jeep slam into the car carrying embri and her dad. I said dad, I'm okay, and i was crying hiss tearically. Reporter: There was a small fire growing in the back of the jeep. He ran over. Doors were jammed. He butted the window out with hgs hands. Reporter: Janel's father pulled out an 18-year-old, but could not rescue the boy's mother or friend. The fire spread too fast. Something has to be done. It can't be done soon enough. Reporter: But chrysler is refusing the recall, ins the government's three-year long investigation is based on an incomplete analysis. The automaker says the vehicles are safe and are not defective. We believe that av chrysler has time to think about this, see the public reaction, they'll do the right thing and recall the jeeps. Janel who can still find remnants on this highway -- seeing it here, burned to ashes is moving and so sad. Reporter: Vows to continue pushing for that recall. Safety advocates say this could be one of the most significant recalls in decades because of the death toll involved. As we said, the government estimates at least 51 people killed in rear-end crashes involving these older jeeps. Diane? What if chrysler continues to say no? Well, chrysler does now have a chance to contest the government and to try to again make its case. But if the government stands firm, this could end up in court.
This transcript has been automatically generated and may not be 100% accurate.