At least one person has been confirmed dead as no other survivors have been located after a Black Hawk helicopter crashed during a training exercise in Florida on Tuesday afternoon.

The UH-60 firefighting helicopter crashed into a marsh near the Leesburg airport in Lake County, Florida, around 40 miles northwest of Orlando, at around 4:00 p.m. on Tuesday, the Federal Aviation Association (FAA) told Click Orlando.

Four people were onboard the helicopter at the time of the crash, and Leesburg Fire Rescue confirmed in a statement on Facebook that none of the passengers have been recovered.

“The crash appears to be a total loss. No survivors have been located. Most of the fire is under control now,” the agency wrote. “US forestry is on scene plowing a line around the scene to prevent any vegetation fires.”

Leesburg Fire Rescue also confirmed that the FAA had been notified of the crash and is scheduled to begin its investigation on Wednesday, while the National Transportation Safety Board (NTSB) told The Daily Mail that several of its investigators were travelling to scene on Tuesday night.

A photo posted to the fire department’s Facebook page showed a large plume of smoke rising from the crash site, while Click Orlando shared aerial footage of the helicopter still engulfed in flames once the sun had gone down.

According to Fox 51, Joe Iozzi, Captain with the Leesburg Police Department, told reporters on Tuesday evening that “at some point, some kind of mechanical failure evidently occurred and the helicopter went into a tailspin.

“The tail separated from the main body of the aircraft, the tail went onto the airport runway area and the main body of the aircraft went back into that swampy, wooded area and fire crews are currently conducting a rescue operation.”

Lozzi said that local police officers were able to talk to witnesses at the scene to ascertain what happened with the helicopter.

Black Hawk helicopters are used regularly by the U.S. military, which operates 2,135 of the H-60 designated aircraft, more of them than any other country in the world, according to the website of its manufacturer Lockheed Martin.

The manufacturer says that there are more than 4,000 of the helicopters in operation worldwide, and describes the craft as “an Armed Helicopter” able to “provide fire suppression when supporting ground troops, as well as armed escort.”

Newsweek has contacted FAA, NTSB, Leesburg Fire Rescue and Lockheed Martin for comment on the crash.