Three dead following medical helicopter crash in KY

(CNN) -- A medical helicopter crashed in Kentucky, killing all three crew members as they returned to their base after transporting a patient, authorities said Friday.

The crash occurred late Thursday night in Clay County.

No patients were aboard the flight, CNN affiliate WYMT reported.

The crew members killed are pilot Eddie Sizemore, paramedic Herman "Lee" Dobbs and flight nurse Jesse Jones, according to the affiliate.

A statement from the helicopter company, Air Evac Lifeteam, said the crew had just transported a patient to a hospital in London, Kentucky. The base is in Manchester.

"We are devastated at the loss of these crew members who we consider family," the company said on its Facebook page. "We have no details regarding the cause of the accident, but will be working with the National Transportation Safety Board in coming days as they conduct their investigation."