DETROIT - The U.S. government's road safety agency is investigating complaints that the Chevrolet Bolt electric vehicle can catch fire.CHICAGO - FEBRUARY 07: 2019 Chevrolet Bolt EV is on display at the 111th Annual Chicago Auto Show at McCormick Place in Chicago, Illinois on February 7, 2019. (Photo By Raymond Boyd/Getty Images) The probe by the National Highway Traffic Safety Administration covers nearly 78,000 Bolts made by General Motors from the 2017 through 2020 model years.The agency says in documents posted on its website Tuesday that it has three reports of fires that began under the rear seat while the cars were parked and unattended.