FORT CAMPBELL, Kentucky (AP) — Nine people were killed in a crash involving two Army Black Hawk helicopters conducting a nighttime training exercise in Kentucky, a military spokesperson said.

Nondice Thurman, a spokesperson for Fort Campbell, said Thursday morning that the deaths happened the previous night in southwestern Kentucky during a routine training mission.

A statement from Fort Campbell says the two HH-60 Black Hawk helicopters, part of the 101st Airborne Division, crashed around 10 pm Wednesday in Trigg County, Kentucky. The 101st Airborne confirmed the crash about 30 mile (48 kilometres) northwest of Fort Campbell. The crash is under investigation.

The helicopters landed in a field near a residential area with no injuries on the ground, Brig. Gen. John Lubas, the 101st Airborne deputy commander, said. One helicopter had five people aboard and the other had four, Lubas said.

Speaking a news conference Thursday morning, Kentucky Governor Andy Beshear said the state would do everything they can to support the families of those killed.

“We’re going to do what we always do, we’re going to wrap our arms around these families, we’re going to be with them for the weeks and days to come,” Beshear said.

Fort Campbell is located near the Tennessee border, about 60 miles (97 kilometres) northwest of Nashville, and the crash occurred in the Trigg County, Kentucky, community of Cadiz.

Nick Tomaszewski, who lives about a mile from where the crash occurred, said he saw two helicopters flying over his house moments before the crash.

“For whatever reason last night my wife and I were sitting there looking out on the back deck and I said “Wow, those two helicopters look low and they look kind of close to one another tonight,'” he said.

The helicopters flew over and looped back around and moments later “we saw what looked like a firework went off in the sky.”

“All of the lights in their helicopter went out. It was like they just poofed … and then we saw a huge glow like a fireball,” Tomaszewski said.

Flyovers for training exercises happen almost daily and the helicopters typically fly low but not so close together, he said.

“There were two back to back. We typically see one and then see another one a few minutes later, and we just saw two of them flying together last night,” he said.

Members of the Kentucky Senate stood for a moment of silence Thursday morning in honour of the crash victims.

“We do not know the extent of what has gone on, but I understand it is bad and there has been a substantial loss of life of our military,” Senate President Robert Stivers told the somber chamber.

Last month, two Tennessee National Guard pilots were killed when their Black Hawk helicopter crashed along an Alabama highway during a training exercise.

The Black Hawk helicopter is a critical work horse for the US Army, providing key security, transport, medical evacuations, search and rescue and other missions. It was a frequent sight in the skies over Iraq and Afghanistan during the wars conducting combat missions and is also used by the Army’s 160th Special Operations Aviation Regiment. Black Hawks were also often used to ferry visiting senior leaders to headquarters locations in the Iraq and Afghanistan war zones.