WASHINGTON, United States (AFP)—The death toll from a UPS cargo plane crashing in Louisville has risen to nine with more fatalities feared, Kentucky’s governor said Wednesday, as search efforts continued and the airport resumed flights.

The McDonnell Douglas MD-11 departing for Hawaii crashed at around 5:15 pm (2215 GMT) Tuesday, shortly after taking off from Louisville Muhammad Ali International Airport.

It exploded into flames as it plowed into businesses adjacent to the airport.

Kentucky Governor Andy Beshear called the tragedy “heartbreaking” and “unimaginable.”

“The number of those lost has now risen to at least 9, with the possibility of more,” he posted on X. “Right now these families need prayers, love and support.”

Beshear said in a prior post that 16 different families had reported loved ones unaccounted for.

“A significant search and rescue mission was underway overnight, which is continuing this morning,” he said.

UPS said in a statement that three crew members were on board the aircraft, adding that “we have not confirmed any injuries/casualties.”

Tuesday’s crash reportedly was the deadliest in the global package delivery giant’s history. Its main hub, Worldport, is in Louisville, where it employs thousands of people.

UPS has halted package sorting operations at their facility.

Video shared by local broadcaster WLKY showed the aircraft’s left engine on fire as it tried to lift off.

By early Wednesday, Louisville Mayor Craig Greenberg said on X that aviation officials had reopened the runway.

A spokesman for the airport, Jonathan Bevin, said the cargo flight “went down three miles (five kilometers) south of the airfield” after taking off.

UPS travels to more than 200 countries via nearly 2,000 daily flights, with a fleet of 516 aircraft. It owns 294 of those planes and hires the rest through short-term leases or charters.

Aerial footage of the crash site showed a long trail of debris as firefighters blasted water on the flames, with smoke billowing from the area.

Beshear said the aircraft hit a petroleum recycling facility “pretty directly.”

The cause of the crash was under investigation by the Federal Aviation Administration and the National Transportation Safety Board.

The crash comes amid the longest government shutdowns in US history. Earlier Tuesday, Transportation Secretary Sean Duffy warned of “mass chaos” due to a lack of air traffic control staff.

“You’ll see mass cancellations, and you may see us close certain parts of the airspace, because we just cannot manage it because we don’t have the air traffic controllers,” Duffy told reporters.

In January, an American Eagle airliner hit a military Black Hawk helicopter outside Washington’s Ronald Reagan National airport, killing all 67 people on both aircraft.

That crash, which ended the country’s 16-year streak of no fatal commercial air crashes, has added to concerns about the US air traffic control system, which some regard as an understaffed operation beset by problems with old equipment.