Delta Air Lines has faced a series of unsettling incidents over the past week, including smoke or haze in the cabin on two flights and a separate crash that injured more than 20 people.

ATLANTA — A Delta Air Lines flight had to return to Hartsfield-Jackson Atlanta International Airport after the flight crew reported a “haze” in the cabin. The crew on Delta Flight 876 to Columbia, S.C. noticed the haze shortly after takeoff. The flight declared an emergency so it would have priority to land.

A Delta flight returned to Los Angeles Saturday night shortly after taking off to Australia when smoke was detected on board in the plane's galley.