LOUISVILLE, Ky. (AP) — UPS has announced it will ground its MD-11 aircraft fleet 'out of an abundance of caution' following a catastrophic crash at its global aviation hub in Kentucky. This decision impacts about 9% of its airline operations.

The tragic accident, which took place on Tuesday, resulted in the deaths of 14 individuals, including the three pilots onboard the ill-fated flight en route to Honolulu.

UPS stated, 'We made this decision proactively at the recommendation of the aircraft manufacturer.' They emphasized that the safety of their employees and the communities they serve is their highest priority.

While the grounding is a cautious step, UPS has not yet specified how long the fleet will remain grounded. Boeing, which owns McDonnell Douglas, has not provided clarity on the rationale behind the manufacturer’s recommendation.

The crash occurred when the cargo plane, moments from takeoff, alerted the crew with a bell sound just 25 seconds before the disaster, with reports of the aircraft barely lifting off while its left wing ignited and an engine tore off. The plane then crashed into the ground, creating an enormous fireball.

Investigators noted that the cockpit voice recorder captured the alarming sound at 37 seconds after the takeoff thrust was requested. The reasons for the alarm remain unclear, though evidence points to a critical failure correlating with the left wing’s fire.

Inman, a member of the National Transportation Safety Board, indicated that determining the exact cause of the alarm and its relation to the fire will form a crucial part of the ongoing investigation.

Former federal crash investigator, Jeff Guzzetti, speculated that the bell likely signaled the engine fire, and acknowledged that this incident transpired past the decision point where pilots could successfully abort the takeoff.

Footage of the crash was widely circulated, depicting the aircraft as it struck nearby businesses, illustrating the magnitude of the disaster.

The UPS Worldport facility is critical to UPS operations, employing over 20,000 personnel and facilitating around 300 flights each day.