Connecticut Light & Power, the state's largest utility, announced Sunday night that it would miss its goal of restoring electricity to 99 percent of its customers by midnight.
Chief Operating Officer Jeffrey Butler apologized, saying that power might not be restored to everyone until Wednesday. About 60,000 customers remained without electricity early Monday.
Gov. Dannel P. Malloy has launched an investigation into the utility companies' response amid a torrent of customer complaints. A fire department has said CL&P jeopardized safety by not quickly clearing roads of downed power lines and branches.
Elsewhere in the region, only a few hundred customers remain without power.