Some residents of a Sheepshead Bay, Brooklyn, block were temporarily evacuated from their homes.

An early morning transformer vault fire on Thursday sparked high carbon monoxide readings.

The underground fire happened at around 3:30 a.m. and left a block of Brigham Street without power. Con Edison says about 53 customers were affected.

The carbon monoxide levels began dropping in about a dozen homes evacuated a couple of hours later.

There is no word yet on when power will be fully restored.