The Pepco power company, which serves the D.C. metro area, drew criticism from many for its response time, but Mallette said, "We're not going to sit here and rate Pepco or any other utility. ... That is one thing that will be dealt with in an after-action issue."

For now, he said, "we're not going to be happy until we have every Marylander back online. ... We have zero tolerance. We want that power back on yesterday."

July Fourth celebrations were canceled in several Maryland locales, including Kensington, Germantown, Rockville and Gaithersburg, officials said. Bone-dry and hot conditions forced fireworks cancellations in other areas.

Traffic lights remain out in many hard-hit locales, including around the nation's capital, yet another reason for headaches.

"A lot of detours, a lot of lights that are out (and) some that are spotty," said Larry Simmons, a frustrated commuter in southern Maryland. "A lot of congestion, a lot of discourteous drivers."