Four deaths are now being blamed on the storm that blew through the mid-Atlantic region Sunday.

Two of the deaths occurred in Maryland. Officials say a 63-year-old man died after running into severe winds and choppy seas while riding a personal watercraft on the Chesapeake Bay.

And a Prince George's County fire spokesman says a woman in a minivan in Beltsville was killed and another injured when the van was crushed by a tree.

Fire spokesman Mark Brady said two women were in the van when it was crushed by a tree at Rhode Island Avenue and Odessa Road. Brady said the victim appeared to be in her 40s and the other occupant was a woman about 60 years old who was taken to a hospital. No other details were immediately available.

In Pennsylvania, police say a 53-year-old woman was apparently electrocuted by a fallen power line in her back yard.

In Loudoun County, Virginia, a six-year-old boy died after a large section of a tree fell on him while he was walking with his family on a path near the Claude Moore Recreation Center in Sterling Sunday. They say heavy winds from a storm caused a large portion of a tree to fall on him.

The boy was taken to a hospital, where he died.

The violent weather knocked out power to more than 400,000 homes and businesses, the largest outage since Hurricane Isabel hit in 2003.

The regional utility Pepco reported more than 230,000 homes and businesses still blacked out Monday morning in Washington and suburban Maryland. And officials say it could be days before power is restored to everyone.

Baltimore Gas & Electric says about 38,000 customers were without service Monday morning.

Alexandria, Virginia, police reported numerous traffic signals were out because of the storm and city officials said about 18,000 Dominion Virginia Power customers were without service Sunday.

The National Weather Service says slightly lower temperatures are expected for the region.

Forecaster Kevin Witt says a cold front clashed with sweltering heat and humidity, causing the storms that brought heavy gusts and rain Sunday.

Witt says high pressure behind the cold front will return temperatures to the mid to upper 80s Monday. He says that's more typical for the area than the high 90s from the previous two weeks.

Witt says wind damage stretched from Hampshire County, West Virginia to Montgomery County, Maryland. He says, in Poolesville, Maryland, there was a report of a 100-foot-long tree that fell.

The weather service will decide Monday whether to send out meteorologists to further survey the storm's reach.

On top of the damage, Metro says trains could be more crowded after the storms cut off power to a dozen stations and affected maintenance efforts.

The transit agency says about 18 backup generators kicked in after electricity to the railroad went out Sunday. Officials say many of those generators continued to be used Monday.

Metro says the power outage prevented crews from providing maintenance to rail cars and having the cars at proper locations Monday morning. In addition, fewer trains are available for morning rush hour because crews were unable to fix all trains with air conditioning problems.

The heavy rain flooded and shut down the Rockville Metro station for some time. A fallen tree between the Shady Grove and Rockville stations halted service briefly on the red line Sunday afternoon.

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