The MD-11 bound for Hawaii veered off course, hitting buildings and hangars. Three crew members and four people on the ground were among the victims. Photo: AP

UPS Flight 2976, a McDonnell Douglas MD-11 trimjet bound for Hawaii, crashed at approximately 17:15 local time with three crew members aboard, according to the Federal Aviation Administration and UPS. Four additional victims were not on the aircraft, officials said.

"The news out of Louisville is bad tonight. The death toll has now reached at least 7. That number is no doubt going to rise," Kentucky Governor Andy Beshear said via X, adding that firefighting efforts and crash investigation were continuing. At the same time, air quality control resources were deployed to the area.

Amateur video broadcast by local television network WLKY showed the left engine on fire while the MD-11 taxied on the runway attempting to take off before exploding, causing a massive column of fire and smoke.

The aircraft, embarking on a 6,920-kilometre journey to Hawaii, carried an estimated 144,000 litres of fuel when it crashed. It followed an erratic course ending nearly 8 kilometres from the airport, crashing into buildings and hangars.

Aerial footage from local television helicopters showed fire spreading across hundreds of metres in an area containing hangars and parking lots, with emergency service beacons and first aid vehicles visible in the distance.

"At this stage, we think the main affected area is the one where the UPS headquarters of two companies is located," Beshear said.

Governor Beshear called for support for victims' families. "Anybody who has seen the images and the video, know how violent this crash is. And there are a lot of families that are going to be waiting and wondering for a period of time," he said.

"We are going to try to get them that information as fast as we can, but if this is a family you know, please give them your support."

National Transportation Safety Board investigators were expected on site Wednesday.

The accident occurred amid fiscal paralysis attributed to the Republican and Democratic inability to reach a congressional compromise, which was increasingly affecting air transport. Shortages of air traffic controllers working without pay since 1 October have caused flight delays and cancellations nationwide for weeks.

Transportation Secretary Sean Duffy warned Tuesday that US airspace risks a partial shutdown if fiscal paralysis extends beyond this week.

UPS halted package sorting at its Louisville facility Tuesday night without announcing resumption timing. The hub, UPS's largest package-handling facility, employs thousands of workers, operates 300 daily flights, and sorts over 400,000 packages per hour.

UPS's airline arm operated approximately 500 cargo planes at the beginning of September, including 27 MD-11s of the type involved in the crash.

The most recent major plane crash in the US occurred on 29 January near Ronald Reagan Airport in Washington when a scheduled aircraft on final approach collided with a military helicopter, killing 67 people.