The investigation into the death of an airline ground crew worker pulled into the engine of a plane during a fatal accident at an Alabama airport will take weeks to complete, authorities said.

The National Transportation Safety Board is investigating the Saturday accident at the Montgomery Regional Airport that claimed the life of an employee for a subsidiary of American Airlines.

The agency said in a statement that the “aircraft was parked at the gate with the parking brake set when a ground support personnel was ingested into the engine.”

The accident is under investigation and a preliminary report is expected in two or three weeks, the agency said.

The accident involved an Embraer 170 aircraft operated by regional carrier Envoy Air, a subsidiary of American Airlines. The flight was set to depart Montgomery for Dallas-Fort Worth before the accident, according to officials.

The airport said a ground crew worker for Piedmont Airlines, another American subsidiary, was killed.

“Our thoughts and prayers are with the AA/Piedmont Airlines/employee’s family and ground crew,” the airport said in a statement.