The Air Force says human error caused a B-52 crew to drop concrete bombs into a Kansas lake this summer.
The bomber dropped nine, 500-pound concrete bombs -- without explosives -- in Kanopolis Lake as the plane neared the Smoky Hill Air National Guard bombing range west of Salina.
No one was injured and no property was damaged in the incident July 19th.
A report from the Eighth Air Force headquarters in Louisiana says bomb system equipment on the aircraft worked properly, but the wrong coordinates were entered into the targeting system.
Officials say the aircrew didn't realize the error until the training weapons were released.
Air Force officials say the air crew was temporarily grounded and went through retraining.