Officials say a technical malfunction at air traffic control amid heavy fog led to a one-hour shutdown of Frankfurt airport, one of Europe's busiest.
Frankfurt airport operator Fraport says 75 flights were canceled between 6.40 a.m. and 7.24 a.m. (0540 and 0624 GMT) Thursday. Air traffic control spokesman Axel Raab says a data link with the German weather service went down.
Twenty-five aircraft were diverted to airports in Cologne and Stuttgart to land. Some later flights were delayed.