Four people were killed after their plane hit a bald eagle in Alaska last month, the National Transportation Safety Board said on Wednesday.
On April 20, a Cessna 172 crashed shortly after takeoff in a wooded area outside of Anchorage, killing pilot George Kobelnyk, 64, co-pilot Christian Bohrer, 20, and passengers Sarah Glaves, 36, and Kyle Braun, 27, according to the Anchorage Police Department. The NTSB said they were part of a photography and surveying flight.
The cause of the crash is still unclear, but after studying the plane parts at the Smithsonian Institution in Washington, D.C., the NTSB released its preliminary findings this week.
Researchers found a foreign substance on the tail section of the plane and determined that it was from an immature bald eagle, Shaun Williams, the NTSB’s lead investigator, told The Huffington Post.
According to the Department of Agriculture, last month's crash is the first fatal civil aircraft accident to follow an impact with a bald eagle. Williams said investigators have not determined whether the bird caused the crash, and will now focus on possible scenarios that could have downed the plane.
"We are going to go back and look at crash dynamics to find out, where did the eagle hit? What effect did the impact have?" Williams said.
Bald eagles don't frequently collide with planes, but it does happen occasionally. Between 1990 and 2015, 219 bald eagles struck aircraft in the U.S., 60 of them in Alaska, Williams said.