A Southwest airlines flight made an emergency landing today after a hole opened in the roof of the plane. Flight 812 was carrying 118 passengers between Phoenix and Sacramento, California. It landed safely at Yuma Marine Corps Air Station, and resulted in only minor injuries. The cause of the hole is not yet known. Passengers recounted hearing an explosion and seeing daylight through the roof. Oxygen masks came down, although some of them malfunctioned, causing people to fall unconscious.