http://www.kcra.com/news/27405181/detail.html
One passenger said they heard an explosion during the flight and could see daylight coming through a hole in the plane.
The KCRA viewer sent in a photo that shows oxygen masks dropping inside the aircraft.
See Images From Inside Plane
“The hole is about 6 feet, oxygen masks are down,” passenger Brenda Reese told KCRA 3. Reese said she was asleep when the rapid descent took place but heard a jarring noise.
A separate picture shows a hole above a luggage compartment.
The FAA said they do not know what caused the decompression.
metal fatigue might sound like an explosion when it gives way