PHOENIX Federal officials said a "fuselage rupture" forced a Southwest Airlines flight to make an emergency landing Friday in an Arizona desert city, and passengers described a large hole at the top of the plane.
The cause of the hole was not immediately known.
"It's at the top of the plane, right up above where you store your luggage," passenger Brenda Reese told The Associated Press in a telephone interview. "The panel's not completely off. It's like ripped down, but you can see completely outside... When you look up through the panel, you can see the sky."
Reese said the plane had just left Phoenix Sky Harbor International Airport for Sacramento, California, when she awoke after hearing a "gunshot-like sound." She said oxygen masks then dropped for passengers and flight attendants as the plane dove.
Terrorism was not suspected because an FBI spokesman in Sacramento, Steve Dupre, said "it appears to be a mechanical issue."
The plane, which was carrying 118 people, landed at a military base in Yuma without any injuries reported, according to the airline. Reese said a flight attendant fell and injured his nose, and said some people "were passing out because they weren't getting the oxygen."
The National Transportation Safety Board said an "in-flight fuselage rupture" led to the sudden descent and drop in cabin pressure aboard the Boeing 737.
Ian Gregor, a Federal Aviation Administration spokesman in Los Angeles, said the pilot "made a rapid, controlled descent from 36,000 feet to 11,000 feet altitude after the incident occurred."
"It dropped pretty quick," said Reese, who provided mobile phone photographs of the cabin damage. The pictures showed a panel hanging open in a section above the plane's middle aisle, with a hole of about 6 feet long.
Christine Ziegler, a 44-year-old project manager from Sacramento, watched as a crew member and a fellow passenger nearby fainted, hitting their heads on the seats in front of them.
Larry Downey, who was seated directly below the hole when it opened, told Phoenix TV station KPNX that "it was pandemonium."
"You could look out and see blue sky," he said.
Julie O'Donnell, an aviation safety spokeswoman for Seattle-based Boeing Commercial Airplanes, confirmed there was "a hole in the fuselage and a depressurization event" but declined to speculate on what caused the incident.
Reese said there was "no real panic" among the passengers, who applauded the pilot after he emerged from the cockpit following the emergency landing at Yuma Marine Corps Air Station/International Airport, some 150 miles southwest of Phoenix and about 40 minutes after takeoff from Sky Harbor.
"It was unreal. Everybody was like they were high school chums," Ziegler said, describing a scene in which passengers comforted and hugged each other after the plane was on the ground.
Gregor said an FAA inspector from Phoenix was en route to Yuma. The NTSB said it also was sending a crew to Yuma.
Gina Swankie, a spokeswoman for Sacramento International Airport, said passengers would be put on another flight to Sacramento later Friday.
"I fly a lot. This is the first time I ever had something like this happen," said Reese, a 37-year-old single mother of three who is vice president for a clinical research organization. "I just want to get home and hold my kids."
Holes in aircrafts can be caused by metal fatigue or lightning. The National Weather Service said the weather was clear from the Phoenix area to the California border on Friday afternoon.
In October 2010, a cabin lost air pressure when a hole ripped open in the fuselage of a Boston-bound American Airlines flight from Miami, also forcing an emergency landing.
In 1988, a Boeing 737 blew open at 24,000 feet when a 20-foot section of the aircraft's upper fuselage ripped off. An Aloha Airlines flight attendant was sucked out of the jet and killed, and 61 passengers were injured.
Meanwhile, two flight attendants reported dizziness and four passengers fainted aboard an American Airlines flight Friday, forcing the pilot to drop the jet's oxygen masks and land in Ohio, an airline spokesman said.
All 132 people on Flight 547 from Reagan National in Washington to Chicago's O'Hare Airport walked off the Boeing 737 after it landed at Dayton International Airport, but two passengers and a flight attendant were taken to hospitals, airline spokesman Ed Martelle said.
The two passengers were able to return to the airport and accompanied their fellow passengers on a replacement plane to Chicago. The flight attendant was admitted for overnight observation, airline spokesman Tim Smith said.
Christina Saull, a passenger from Washington, said there had been problems with the air conditioning and cabin-pressurization system before the plane took off, and maintenance personnel went into the cockpit of the plane on the ground in Washington, the Dayton Daily News reported.
After the flight took off, two women passed out and passengers started complaining about fumes or being lightheaded, Saull told the newspaper. Saull said she didn't smell anything, but a few minutes later, "they were announcing they were going to drop the masks."