Montgomery County's "Ride On" bus pool is coming under scrutiny as the National Transportation Safety Board investigates the safety of the fleet.
The NTSB is looking for manufacturing defects on several of the buses to determine if the fleet needs to be recalled. The probe comes after six fires were reported on some of the buses in Montgomery County in the past three years.
The county has said it plans to remove the buses from service in the next 18 months, but the union representing bus operators says that's not soon enough. The company that sells the vehicles in question, Champion, has issued a recall of some models in the past.
In the meantime, the union filed a grievance claiming the county has failed to enforce safety and health obligations under its collective bargaining agreement.