A medical transport helicopter crashed in coastal South Carolina, killing all three people on board, authorities said Saturday, according to AP. The company that owned the helicopter, Texas-based Omniflight, said a pilot, flight nurse and paramedic were on board when it crashed Friday night. National Transportation Safety Board investigators were en route to the scene Saturday. Agency spokesman Peter Knudson says no patients were on board the helicopter, which had dropped off a patient at about 9:35 p.m. Friday in Charleston, about southwest of Georgetown County. In a statement, the company confirmed that the American Eurocopter AS350B2 took off from Charleston around 11 p.m. Friday and was headed to Conway, a city about 50 miles north of Georgetown. Federal Aviation Administration spokeswoman Kathleen Bergen says the pilot last radioed air traffic control at 11:05 p.m., saying the crew was about four miles from an airport near Charleston and had it in sight. The helicopter crashed shortly thereafter, at about 11:30 p.m., Knudson said. A thunderstorm moved through the area shortly before the crash, according to the National Weather Service. Authorities have not said if weather conditions contributed to the accident. On its Web site, Omniflight says the company operates 100 aircraft from 72 bases in 18 states. In a statement, the company said its 1,000 employees were coping with the tragedy. «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,» the company said.