SALEM, Ore. (AP) – Oregon military officials say a sonic boom that sparked widespread concern on the Oregon coast that an earthquake occurred earlier this week was caused by an aircraft that “inadvertently went supersonic”.

The 142nd Wing of the Oregon Air National Guard said Wednesday that Tuesday’s sonic boom was caused by airplanes.

142 Wing spokesperson Staff Sergeant Steven Conklin said the military was allowed to fly supersonic 15 miles off shore, but pilots should not have the nose of the jet pointed towards the coast.

The 142nd Wing in a Facebook post apologized for worrying residents of the coast.

“During this training we inadvertently went supersonic and caused a sonic boom while pointing slightly towards the coast over 15 miles from land,” 142 Wing said on Facebook. “We understand this has raised concerns among our coastal residents and we sincerely apologize for it. “

Conklin said the plane was a single-pilot F-15C and a two-person F-15D Eagle.

As speeds fluctuate during training, “it is not uncommon to go supersonic during basic fighter maneuvers, sometimes referred to as air combat,” he said.