The National Transportation Safety Board and the Federal Aviation Administration are investigating an incident involving a ground crew worker who was badly injured at Philadelphia International Airport on Friday evening, during pushback for a departing Aer Lingus flight. Police identified the victim as a 60-year-old man, and said he was caught under an airplane moving tug and the wheel of the plane. The man was placed in critical condition at Penn Presbyterian Medical Center, police said.

"The NTSB is investigating this accident," a spokesman for the safety board said. "We're still at the early stages."

The Aer Lingus flight, bound for Dublin, was being operated by a different airline, ASL Ireland. The injured worker was employed by a separate ground handling company, Dubai-based Dnata. According to ASL spokesman Andrew Kelly, the ground handling crew had control of the airplane during the incident, which ASL also reported to safety regulators in Ireland.

Dnata confirmed the injured worker is their employee. "We are providing him and his family with all possible support," a spokesman said. The company didn't comment on how the incident occurred, or the type of work the man was performing when it happened.

"A formal investigation is currently being undertaken to determine the facts and we will continue to work with the relevant authorities," the Dnata spokesman said.

Airlines routinely contract with service providers to handle the pushback from the gate before takeoff.

Philadelphia International Airport spokeswoman Mary Flannery said PHL reported the incident to federal authorities Friday night. "The NTSB has requested basic information about this incident and the airport responded."