A medical helicopter responding to a call to airlift a hiker with breathing problems crashed Sunday southeast of the Alabama city of Birmingham, leaving two of its crew dead and sending the third to a hospital, authorities said.

The Eurocopter EC130 crashed near the community of Chelsea in Shelby County with the three crew aboard, the Federal Aviation Administration said in an email to The Associated Press.

Shelby County Sheriff’s Office Chief Deputy Clay Hammac told news outlet al.com that the downed craft was a medical helicopter called to evacuate a hiker suffering from breathing problems and chest pains.

Deputies had set up a landing area for the helicopter, he added.

A deputy called 911 to report the crash and said that one of the three crew members was pronounced dead at the scene, according to the report. Two others were taken to a hospital, where one of them was pronounced dead, it added.

The condition of the third crew member was not immediately available.

The hiker was transported separately and made it to a hospital safely, according to Hamma. The hiker’s condition also was not known.

“Our deputies did the best they could to render aid,” Hammac said. “The helicopter was on fire.”

Emergency crews spent hours at the site of the charred wreckage and law enforcement officers planned to secure the site overnight while the investigation continues, according to the report.

The National Transportation Safety Board said in a tweeted statement that it would lead the investigation into the crash, assisted by the FAA. Those agencies had no preliminary information on a possible cause.

Chelsea is about 20 miles (32 kilometers) southeast of downtown Birmingham.