West Virginia coal tycoon Chris Cline was rushing his 22-year-old daughter to a Florida hospital for a medical emergency when their helicopter plunged into the Bahamian sea, according to a report.

Kameron Cline, 22, began experiencing the unspecified medical issue while on her dad’s private island near Grand Cay, WPBF reported on Friday.

Relatives called authorities when the chopper failed to reach Fort Lauderdale, Delvin Major, chief of the Bahamian Air Accident Investigation Department, told the Palm Beach Post on Friday.

A major Republican donor worth $1.8 billion, according to Forbes, Cline was on board the chopper with Kameron and several of her friends when it dropped into the Atlantic Ocean minutes after taking off around 2 a.m.

Cline, who started working in the West Virginia mines at the age of 15 before building his own empire, died a day before his 61st birthday.

The wreckage was discovered on the ocean floor about two miles off the coast of Cline’s private island.

The cause of the crash is under investigation. Meteorologists have said weather was not a factor.