The UPS cargo plane that crashed in Louisville Tuesday was 34 years old and was very recently grounded for more than a month for critical repairs to its fuel tank, according to a report.

The MD-11 plane was stranded in San Antonio from Sept. 3 to Oct. 18 as it received a permanent repair to fix a crack in the fuel tank before getting back in the sky, according to Federal Aviation Administration maintenance records reviewed by The Wall Street Journal.

At least 12 people — including a child — were killed after the plane lost its engine, nose-dived and crashed in a fiery blaze seconds after taking off from Muhammad Ali International Airport in Louisville, officials said.

The crash sparked a massive inferno that consumed the enormous aircraft and spread to nearby businesses, harrowing footage shows.

The MD-11 has the second-worst safety record of any commercial aircraft still in service, according to safety data published by Boeing earlier this year. 

Planes more than 30 years old are typically retired in the cargo business, according to the Journal. In just the past three years, UPS rival FedEx has retired 20 MD-11s.

The average age of a UPS-owned cargo jet is around 22 years old, and its average MD-11 is 31.

UPS has nearly 300 aircraft in its fleet, 29 of which were MD-11s.

The plane was parked at a facility owned by ST Engineering, which told the Journal it provided airframe maintenance to the aircraft.

Following repairs, the jet flew to California and Baltimore before returning to Louisville, which is home to UPS’ aviation hub, flight records show.

The Honolulu-bound jet, which had three UPS employees on board, was carrying about 50,000 gallons of fuel when it crashed around 5:15 p.m. Tuesday night.

The National Transit Safety Board [NTSB] is investigating what caused the fire, which broke out on the plane’s wing and caused the engine to fall off — but officials said the probe will likely take more than a year before findings are released to the public.

Airport security video “shows the left engine detaching from the wing during the takeoff roll” before it broke apart, said Todd Inman, a member of the National Transportation Safety Board.

“There are a lot of different parts of this airplane in a lot of different places,” he said, describing a debris field that stretched for half a mile.

Twelve people were killed, but that number could rise, according to Kentucky Gov. Andy Beshear. 

Authorities were still looking for a “handful of other people” but “ do not expect to find anyone else alive,” he said.

The child who died was with a parent at the car parts business that was struck by the plane.