Summary:
A piece of an aircraft wing that came loose and struck windows has sparked a safety investigation.

Full article:
WASHINGTON (CNN) -- The National Transportation Safety Board said Thursday that it is investigating an incident in which a panel separated from the wing of a Boeing 757 while it was in flight last week. iReporter and Flight 1250 passenger Paul Shepherd took this photo of the damage through the aircraft's window. The incident occurred Saturday on US Airways Flight 1250 from Orlando, Florida, to Philadelphia, Pennsylvania, the NTSB said in a statement. The separation occurred over Maryland. The aircraft landed in Philadelphia about 30 minutes later, and none of the 174 passengers or six crew members aboard was injured. The panel, on the trailing edge of the upper side of the left wing, broke loose and struck several windows toward the rear of the aircraft, causing the outer pane of one window to crack, the agency said. Pressurization of the cabin was not compromised. The wing panel has not been located. NTSB investigators are using a computer program to pinpoint the area where it might be and will notify local authorities that an aircraft part may be there, the statement said. The plane's cockpit voice recorder and flight data recorder have arrived at the NTSB laboratory in Washington, the agency said, and are being evaluated. E-mail to a friend .