One person is dead and nine others were airlifted to hospitals in Florida and the Bahamas after a boat exploded on Saturday, according to the U.S. Coast Guard and Royal Bahamas Police Force.

Shanta Knowles, superintendent of police for the Royal Bahamas Police Force, confirmed to NBC News that an American woman died in the explosion, but said her identity would not be released until her family had been notified.

Ten Americans and two Bahamians were aboard the boat when it exploded, according to officials.

Four people were airlifted to a hospital in Florida and five others were taken to Princess Margaret Hospitalin Nassau, on New Providence Island, Bahamas, Knowles said. Two others who were aboard the boat were not injured, Knowles said.

"Investigators are still trying to determine what went wrong," Knowles said of the explosion.

Brian Schaffer told NBC News his niece Stefanie Schaffer, 22, was among those injured in the explosion. He said his niece, who has participated in ballet and sports her entire life, had both of her legs amputated below the knee after the explosion.

"We heard she is in a medically-induced coma, and I don't think she knows that she doesn't have any legs left," Brian Schaffer said, adding that doctors are waiting for the 22-year-old to stabilize before flying her to the United States.

Stefanie' Schaffer's sister, mother and stepfather, who were with her at the time of the explosion, sustained non-life-threatening injuries, according to a GoFundMe page set up for the family's medical expenses.

The U.S. Coast Guard's seventh district, which encompasses Florida and is headquartered in Miami, received a call from the Royal Bahamas Police Force at approximately 11 a.m. on Saturday asking for assistance with those injured in the explosion, according to a press release.

A HC-130 Hercules airplane crew with two medical personnel from Air Station Clearwater deployed and transported the boaters to the air station where emergency medical services awaited.

Names and conditions of the other passengers have not been released. An investigation into what caused the explosion is ongoing.