Lt. Don Michalosky with the Cuyahoga County Sheriff's Office says a message was misunderstood Friday morning while NASA was conducting a test of its automated emergency notification system. He says someone who received the message didn't realize it was a test.
Michalosky says he didn't know the specifics of the message but says a story spread that there was a gunman in the building.
An "all clear" announcement went out shortly before 11 a.m. at the sprawling NASA Glenn Research Center next to Cleveland's airport.
A retired NASA Glenn safety officer says false alarms are common at the complex.