Investigators point to an underground electrical issue as the likely cause of the fire.
Con Edison asked some customers in Brooklyn and Queens to conserve energy following a series of manhole explosions on Wednesday.
FDNY officials responded to reports of a manhole fire in front of 29-19 Newtown Ave in Astoria on Saturday.
A manhole fire caused more than 300 Con Ed customers to lose power on the Upper East Side.
At least three people were injured and cars and storefronts were damaged in the manhole explosion in Midtown early Sunday morning.
Two underground Con Edison service boxes caught fire overnight Monday, leaving 53 customers in two buildings in Brooklyn without power.