Police and federal aviation officials are investigating the death Thursday night of a person who was on a runway at an Austin, Texas, airport as a Southwest Airlines Co. jet landed.

A pilot of Southwest Flight 1392 landing at Austin-Bergstrom International Airport reported seeing a person on the runway shortly after the jet touched down at 8:12 p.m. local time, the Federal Aviation Administration said in a statement.

An airport employee later found a body on the runway. FAA investigators are on their way to the site to assist the Austin Police Department, the FAA said in its statement.

The death appears to be the first involving a large passenger airline in the U.S. since a woman died on April 17, 2018, after an engine failed and debris struck a window, causing her to be sucked partly out of the plane on a flight from New York to Dallas.

It’s not clear how the person was able to get onto the runway. Airports are required to have security systems in place to prevent intruders from accessing tarmac and runway areas.

The National Transportation Safety Board, which is charged with investigating aviation accidents, is still gathering information about the incident, spokesman Terry Williams said in an email.