DETROIT — Federal investigators say an 18-year-old pilot ran out of gas before his plane crashed-landed and took out a power line that electrocuted a woman in Detroit.

The pilot was towing an advertising banner during the June 2016 Ford Fireworks show when the engine of his Cessna 150L stopped, the Detroit News ( ) reported.

The National Transportation Safety Board recently concluded that the pilot ran out of gas after flying too long.

The pilot crash-landed 2 miles short of a local airport and suffered only scrapes. But investigators said the plane toppled a power line that hit and electrocuted 38-year-old Theresa Surles as she walked to the show. She died nine days later.

The pilot hasn’t been charged with any crimes.

Investigators said the crash-landing may have been the second time that month the pilot landed without fuel on a banner-towing flight, referring to a “deadstick” landing they allege he carried out at a Wisconsin airport less than three weeks earlier.

The pilot first denied being in Wisconsin, then told investigators he was “running low on fuel” when landing.

The federal agency alleged he also may have fallen asleep during the Detroit flight, but the pilot denies the allegations. Investigators allege that an unidentified banner pilot reported the teen didn’t answer his radio while flying in “large pitch oscillations,” and later told the banner pilot that he had fallen asleep.

According to FAA records, he remains a licensed commercial pilot and certified aviation instructor.

“I’m surprised the FAA hasn’t revoked his license,” said Don Moss, a pilot who runs a consulting company for aviation accident investigations.

“Good pilots don’t have to just have good flying skills, they have to exercise good judgment. And from the sound of it, he has not.”

Information from: The Detroit News,