A medical transport helicopter crashed in southern U.S. state of South Carolina on Friday night, killing all three people on board, the company which owned the helicopter said Saturday.

"Omniflight is deeply saddened by the tragic loss of its crew members and wishes to express its deepest regrets and sincerest condolences to the families and friends of those who lost their lives," Texas-based Omniflight said in a statement.

According to the company, a pilot, flight nurse and paramedic were on board when the American Eurocopter AS350B2 crashed at about 11:30 p.m. on Friday night. No patients were on board when the tragedy took place.

The copter took off from Charleston, South Carolina, at around 11 p.m. local time on Friday and was destined to another city of the coastal state -- Conway.

Omniflight said its employees were dealing with the tragedy. Investigators from the U.S. National Transportation Safety Board were reportedly en route to the crash scene on Saturday.

There was no immediate report about what contributed to the crash. U.S. National Weather Service said a thunderstorm moved through the region shortly before the crash.