The Federal Aviation Administration investigation after an evacuation slide fell off a plane and into a suburban Boston backyard.
Authorities say no one was hurt by the mishap as the jetliner, which was flying from Paris, France, approached Boston Logan International Airport.
Airline workers discovered that the right rear slide was missing from the plane after it landed.
A Delta Air Lines spokeswoman confirmed to the Boston Herald that the uninflated slide fell around noon on Sunday, local time.
The Federal Aviation Administration says the pilot reported a loud noise as the plane approached Logan Airport and landed safely.
Police in Milton, south of Boston, alerted the agency that the slide had been found in a resident's yard.
Wenhan Huang told The Patriot Ledger that he was doing yard work when the slide took out several branches of his Japanese maple.
His neighbour, Stephanie Leguia, was feet from where it fell and fears it could have killed someone.
"Our maintenance team is inspecting the aircraft; at this time we do not have any additional information," Delta told CNN in a statement Monday. "The flight landed without incident and taxied to the gate under its own power."