The dead fetus found on an American Airlines plane at New York’s LaGuardia airport was left there by a pregnant teenager who suffered a miscarriage during the flight. A cleaning crew found the body inside the Airbus A321 at about 7:30 a.m. Monday at Hangar 5, sources told the New York Post. Law-enforcement sources said an 18-year-old from Brooklyn left the fetus on the flight after it touched down in Queens. The flight had already landed and all the other passengers had left the plane when the pregnant woman rushed to the bathroom with her twin sister, telling crew it was an “emergency,” the sources said. A flight attendant told police the teenager looked ill when she came out of the bathroom. She is reported to have checked into Kings County Hospital at 12:30 a.m. Tuesday. NBC New York reports that the teen told authorities that she “didn't know she was pregnant,” and police are reportedly investigating that claim.