Authorities on Long Island are investigating the possibility that a black oily substance leaked from an airplane and fell onto a homeowner’s backyard in Malverne.

A neighbor tells Newsday Saturday that the sludge pelted the patio of a home on Nassau Boulevard in Malverne at about 9:30 p.m. Thursday.

A Federal Aviation Administration spokeswoman says the agency will begin an investigation on Monday. The spokeswoman couldn’t immediately confirm if the substance came from an aircraft.

She says if they do determine the sludge come from a plane they plan to track down the aircraft’s operator and have them check the plane for any leaking or maintenance issues.

(Source: NBC New York)