HARPERS FERRY, W.Va. (AP) — An engineer error caused a CSX freight train to derail as it crossed the Potomac River near Harpers Ferry, West Virginia, sending two cars into the water and damaging a footbridge that is part of the Appalachian Trail, according to a report from the Federal Railroad Administration.

Seven empty train cars in total derailed in the December 21 incident and no one was injured.

The recently released report said the engineer used excessive force to make a movement with the brakes still applied, The Journal reported.

The derailment closed access to some parts of Harpers Ferry National Historic Park and the Chesapeake & Ohio National Historic Park.

Repairs to the footbridge are underway and are expected to be completed in late July.