'Like a missile coming down' - Nine killed in fiery Florida jet crash

US media reports and flight analysis indicate that the jet was plummeting hundreds of feet per second before crashing.

In air traffic control audio recorded moments before the crash, the pilot of the aircraft can be heard saying the plane was descending 10,000 feet per minute, according to the BBC's US partner CBS News.

Then the pilot declared an emergency, yelling, "We are in an overspeed condition descending 20,000 feet per minute," CBS reported.

"We're gonna crash ... We're out of time," the pilot told the tower.

Unverified footage posted on social media shows what appears to be a dash-camera recording of the moment of the crash.