CLARKSVILLE, Tenn. — An Army report says an improperly installed part caused a helicopter to crash in rural Tennessee, killing the two 101st Airborne Division pilots aboard.

A U.S. Army Aircraft Incident Report obtained by USA Today Network-Tennessee says the Apache helicopter, which took off from Fort Campbell in December 2015 on a routine training mission, essentially came apart in midair before crashing to the ground and bursting into flames.

The report says investigators found fault with work performed by three soldiers who replaced bearings on the helicopter in November 2015.

The report redacted the soldiers’ names and specific explanations of what was done wrong, but recommended more inspections when repairs are made.

Fort Campbell officials declined to comment on the report. The Army post is on the Kentucky-Tennessee border, about 60 miles (97 kilometers) northwest of Nashville.