After six RideOn buses caught fire in three years in Montgomery County, Md., a federal investigation has begun into the cause of the blazes.
The National Highway Transportation Safety Administration is investigating the vehicle involved in three of the fires, which was manufactured by Navistar between 2007 to 2010.
The fires have been linked to problems with the buses' brakes, and while no one has been injured in any of the incidents, passengers want to know why the fires have happened.
"If people are taking it as their main form of transportation, it needs to be in better shape," said passenger Melissa Davis.
Montgomery County said there is already a plan in place to remove these models of vehicles off the streets over the next few months, not because of safety issues, but because the buses have had mechanical problems and are unreliable.
The bus operators' union doesn't agree with the plan and has filed a grievance to say the buses need to go now.
"You look at all those buses and you see ... if there is a fire, there's only one way out for those passengers," said Melvin Ransome, a RideOn bus operator.
It's currently unclear how long this investigation will take, and the government said there are around 800 of these buses in operation around the country.
A video of a bus on fire from December 2010 comes from ABC7 news partner WTOP.