The blast occurred about 6:30 a.m. followed by a smoky fire involving an Atlantic City Electric underground service line installed in the 1930's.
"Upon arrival, our crews discovered there was a manhole explosion, and there are three other manholes that are involved, some of them had smoke and fire," Sandra May of Atlantic City Electric said.
Though at least one manhole cover blew off, no one was injured along the stretch of Pacific Avenue near Boardwalk Hall.
Only six customers lost power including a pair of what some euphemistically call gentlemen's clubs.
Down the street, a deli's power was restored quickly, but owner Kahdim Hussain says by his count, this is the third underground electrical fire that's closed his business in two weeks.
"The fire comes out from the hole, very nasty smoke, you can't even breathe and they evacuate the area," Hussain said.
Hussain thinks Atlantic Electric is just patching a crumbling network.
"They should upgrade all the lines, spend some money instead of putting all the money in their pocket," Hussain said.
Atlantic Electric confirmed there had be a fire in this same area last weekend.
The cause of that fire and today's blast is still under investigation.
As for when power will be restored?
The electric company says it would work around the clock, but would not or could not give an estimated time when it expected to have everyone back on line.
The Associated Press contributed to this report.