LOUISVILLE, Ky. (AP) — UPS will ground its fleet of MD-11 planes out of an abundance of caution following a deadly crash at its global aviation hub in Kentucky, the company announced late Friday.

The MD-11 aircraft make up about 9% of its airline fleet, according to the company.

We made this decision proactively at the recommendation of the aircraft manufacturer, the statement said. Nothing is more important to us than the safety of our employees and the communities we serve.

UPS stated that the fleet will be grounded temporarily, although the exact timeline for resumption is unclear. Boeing, which acquired McDonnell Douglas in 1997, has not yet responded to inquiries about the recommendation's specifics.

Tragically, the crash, which occurred Tuesday at UPS Worldport in Louisville, resulted in the deaths of 14 individuals, including all three pilots aboard the MD-11, which was en route to Honolulu.

According to National Transportation Safety Board member Todd Inman, the cargo plane was close to becoming airborne when a bell rang in the cockpit. For the subsequent 25 seconds, the crew struggled to manage the aircraft, which had barely lifted off the runway while its left wing was ablaze and missing an engine before crashing back to the ground in a fiery explosion.

Inman stated that the cockpit voice recorder documented the bell sounding approximately 37 seconds after the crew requested takeoff thrust. Investigators have not yet established the reason for the bell, but they confirmed that the left wing was indeed on fire, and the associated engine had detached.

Former federal crash investigator Jeff Guzzetti noted that the alarm likely signaled an engine fire, indicating the pilots might have been past the decision point to abort the takeoff safely. They’ll need to conduct a thorough investigation into the crew's choices at that critical moment, Guzzetti said.

As part of the investigation, dramatic video footage has surfaced capturing the aircraft clashing into nearby businesses and erupting in flames, providing critical evidence from various perspectives.

UPS Worldport is the company's vital hub, employing over 20,000 people and accommodating around 300 flights daily, managing more than 400,000 packages every hour. Operations at the facility resumed Wednesday night with the Next Day Air, or night sort, operations, as reported by UPS spokesperson Jim Mayer.