A MTA worker is in serious condition after he fell through a sidewalk shaft in Brooklyn.

The man was lowering electrical cables through the sidewalk shaft near the corner of Fulton and Downing streets in Bedford-Stuyvesant at about 11:30 am this morning when he fell to the bottom of the transformer shaft, which was 20 to 30 feet below.

Emergency services took the man to Kings County Hospital, where he is in serious condition.