Water hit an underground transformer early Tuesday morning causing a loud bang and power outages in Philadelphia's Rittenhouse Square neighborhood.
The blast occurred underground near the intersection of 18th and Sansom streets around 4:30 a.m.
Officials shut down both lanes of 18th Street between Walnut and Chestnut streets for about 90 minutes after the explosion.
The road reopened to traffic shortly after 6 a.m., however PECO expects its crews to continue repair work through most of Tuesday.
Police at the scene tell NBC10 the malfunction created a loud bang, which alarmed nearby residents. No fire came about as a result of the transformer trip.