Worn connecting hardware likely caused the left engine to detach from a UPS cargo plane that crashed in Louisville, Ky., the NTSB said.

The images are part of the National Transportation Safety Board's preliminary report, released Nov. 20.

Worn connecting hardware likely caused the left engine to detach from a UPS cargo plane that crashed in Louisville, Ky., the NTSB said.

The deadly 4 November plane crash killed over a dozen people and left dozens more injured.