A Seattle-bound plane was forced to make an emergency landing after the pilot suffered an apparent heart attack onboard, officials said.

United Airlines flight 1603 was diverted to Boise, Idaho, after the unidentified pilot passed out aboard the Boeing 737-900 shortly before 8 p.m., an airport spokeswoman said.

“We got a man down,” a co-pilot told the control tower before landing, according to audio released by LiveATC.net.

“Chest compressions going on right now. I’m not sure too much right now the status.”

The pilot was rushed to Saint Alphonsus Regional Medical Center, but he died overnight, officials told ABC News.

The 161 passengers on the flight were transfered to another plane that brought them to Sea-Tac Airport early Friday, officials said.