Flights were halted after a ground crew worker was killed in an industrial accident on the ramp at Montgomery Regional Airport in Alabama on Saturday, Reuters reports. Two people briefed on the initial investigation said the worker was killed in an accident involving one of the airplane’s engines, which was running, the news agency said. The Federal Aviation Administration is investigating the incident, which took place where an American Airlines plane was parked at a gate after arriving from Dallas. All inbound and outbound flights are grounded indefinitely, the airport said in a statement. The worker has not been identified, but was an employee of American Airlines and Piedmont Airlines. “Our thoughts and prayers are with the family of the deceased,” the airport said.