The NTSB confirmed a UPS cargo plane's left engine separated during takeoff before a fatal Louisville airport crash that killed 12 people and injured 11 others Tuesday.

UPS Flight 2976 crashed Tuesday evening as it departed Louisville Muhammad Ali International Airport for Honolulu, according to the FAA.

Approximately 9% of the UPS fleet is made up of MD-11 freighter planes. All were grounded Nov. 7 amid an ongoing probe into a deadly Nov. 4 crash.

We have viewed airport CCTV security coverage, which shows the left engine detaching from the wing during the takeoff roll,” National Transportation Safety Board (NTSB) Member Todd Inman said.

Surveillance footage showed the left engine of the UPS cargo plane that crashed on Tuesday in Kentucky, detached from the wing, an official said.

The engine and pylon detachment is similar to the American Airlines Flight 191 crash at O’Hare International Airport in 1979. The DC-10’s left engine detached during takeoff, causing the plane to crash, killing 273. The DC-10 is the MD-11’s predecessor. The NTSB faulted improper maintenance as part of its investigation into the crash.

Two days after a UPS plane crashed in Louisville killing at least 13 people, newly released dashcam video appears to show that two of the jet's engines were already gone after takeoff.

The grim task of finding victims from the firestorm that followed a UPS cargo plane crash in Louisville, Kentucky, has entered a third day