WASHINGTON – Millions across the mid-Atlantic region sweltered Saturday in the aftermath of violent storms that pummeled the eastern U.S. with high winds and downed trees, killing at least 13 people and leaving 3 million without power during a heat wave.

Power officials said the outages wouldn't be repaired for several days to a week, likening the damage to a serious hurricane. Emergencies were declared in Maryland, West Virginia, Ohio, the District of Columbia and Virginia, where Gov. Bob McDonnell said the state had its largest non-hurricane outage in history, as more storms threatened. "This is a very dangerous situation," the governor said.

In West Virginia, 232 Amtrak passengers were stranded Friday night on a train that was blocked on both sides by trees that fell on the tracks, spending about 20 hours at a rural station before buses picked them up. And in Illinois, storm damage forced the transfer of dozens of maximum-security, mentally ill prisoners from one prison to another.