Drone activity caused officials to close airspace over one of the United States’ most critical Air Force bases for almost four hours late Friday and early Saturday, according to a base spokesperson and a Notice to Airmen posted on a federal website. Bob Purtiman, chief of public affairs for the 88th Air Base Wing at Wright-Patterson Air Force Base in Ohio, said that the airspace remained restricted for approximately four hours while authorities monitored the situation, CNN affiliate WHIO reported. #CNN #News