Update: For storm damage and recovery information, please click here for Saturday's follow-up story.

A fast-moving line of dangerous storms knocked out power to more than 1.5 million customers in the D.C. area Friday night.

A day of record-shattering heat ended with severe thunderstorms that rushed through the metro area with strong winds and an impressive lightning display.

The storms produced hurricane-force winds in excess of 80 mph. Gusts of 82 mph were reported in the Reston area.

On Saturday morning, the Virginia Department of Emergency Management confirmed that four people had died due to the storm in the Commonwealth.

The National Weather Service reported a tree fell on a car in the area of Old Keene Mill Road and Bauer Drive in Springfield, Va. shortly before 11 p.m., killing 27-year-old Khiet Nguyen of Burke.

One person also died as a result of a tree that fell into a house in the 8100 block of Carr Place in Springfield. The cause of the other two fatalities are unknown at this time.

Fairfax County medics managed to revive a man who was either struck by lightning or came into contact with a live wire. Fairfax County officials said more than 100 homes were damaged by fallen trees.

Extensive power outages have been reported. To view the latest power outage numbers, click here.

Pepco and Dominion said some customers could be without power for multiple days, which could be very dangerous for some as the heat wave continues through the weekend.

The entire town of La Plata, Md. was reported to be without power. That is expected to be the case for several hours today.

All the campuses of Northern Virginia Community College are closed for Saturday, as is Montgomery College in Maryland.

The Washington Suburban Sanitary Commission (WSSC) has issued mandatory water restrictions for both Montgomery and Prince George's Counties in Maryland due to a power failure at WSSC's two water filtration plants. Customers have been asked to stop all outdoor water use and use water indoors only as necessary.

Congressional Country Club in Bethesda was scheduled to host the third round of the PGA Tour AT&T National Saturday. However, on Saturday morning, the tournament announced that the course would be closed to all tournament spectators and volunteers.

Tournament officials said that tickets for Saturday's round would be honored Sunday. It is not clear if play will take place today.

Amtrak service between Washington and Philadelphia was halted until 9 a.m. Saturday while crews repaired damage to the tracks.

West Virginia Gov. Earl Ray Tomblin declared a state of emergency after more than 500,000 customers in 27 counties were left without electricity.



There are several reports of trees and power lines down and roads blocked in the area.

In the 2700 block of 31st Street NW, two were hospitalized -- one in critical condition -- after a tree fell on a car. A firefighter told News4's Shomari Stone that the roof was blown off the top of a building in the 1900 block of U Street NW. That building was evacuated.

Metro reported a downed tree caused single-tracking between Dunn Loring and West Falls Church.

Metro also reported suspended rail service between Grosvenor and Shady Grove due to a power outage and delays on all lines because of the weather. Blue Line service between Largo Town Center and Addison Road was restored when a power outage was resolved about midnight.

Metrobuses also are delayed, as they are stuck in the same traffic as other motorists dealing with downed trees.

Stone reported portable toilets were blown on to Independence Avenue near the Washington Monument, blocking the roadway.

The Heat Before The Storms:

The high temperature was 104 degrees at Reagan National Airport Friday afternoon, setting a record not only for the day, but for the entire month of June. Last year we set a record with a 102-degree day in June.

The previous June 29 record of 101 degrees was set in 1874 and tied in 1934. In the past 142 years, D.C. has seen the temperature reach 104 degrees only 10 times.

A record was set at Dulles International Airport, too. It's reached 102 degrees there. The previous record was 95. The high reached 102 at Baltimore-Washington International Thurgood Marshall Airport, but that was 3 degrees shy of the record set in 1934.

The storms aren't likely to offer the mercury much of a break. We could be in the record heat business again Saturday, and all the rain will make it feel even muggier.

The heat index -- which factors in humidity -- reached 112 degrees for Washington and got up to 117 in Leesburg, Va.; 112 in Fredericksburg, Culpeper and Manassas in Virginia; 114 in LaPlata, Md.; and 112 in Frederick, Md., according to Storm4 meteorologist Doug Kammerer.

On the Billy Goat Trail, a hiker was overcome by the heat and had to be rescued by boat.

Nine Girl Scouts at an event in Benedict, Md., were taken to hospitals because of heat exhaustion. Several others were taken to the Benedict Fire Department to cool off.

At the Martin Luther King Jr. Memorial, seven children were taken to a local hospital with heat exhaustion. They are expected to be OK.

There's a chance for more storms Saturday and Sunday. The storms are not expected to be as severe as Friday's, but Kammerer is not ruling it out because of the heat, which gave Friday's storms their energy.

There's also a chance to tie a record high at Reagan National and Dulles on Saturday, said Storm 4 meteorologist Kim Martucci. The high of 100 was set in 1959, and it is possible we could reach triple digits on Saturday. The all-time high at Dulles on Saturday is 98, and once again that record could be broken.

An excessive heat watch will be in effect from Saturday morning through Saturday evening.

Because of the advisory, Ride On will provide extra bus service for spectators going to the AT&T National at Congressional Country Club in Bethesda.

Temperatures will slowly -- and we mean slowly -- decrease after Saturday.

Sunday's high could reach 99, but Monday's high may only(!) hit 94, followed by 94 Tuesday, 93 on the Fourth of July and 90 on Thursday.

To help residents beat the heat, the D.C. Department of Parks and Recreation is extending swimming pool hours. Click here for more information.

D.C.'s Homeland Security and Emergency Management Agency advised people take the following precautions:

Stay indoors as much as possible.

Turn on the air conditioner or fan.

DO NOT leave children or pets in vehicles.

Pay special attention to young children, the elderly and the mentally ill.

Drink plenty of water.

Wear light-colored, lightweight and loose-fitting clothes.

Apply sunscreen at least 20 minutes before going outside (SPF 15-30 is best).

Limit exposure to the sun (the sun is most powerful between 10 a.m. and 3 p.m.).

Watch for heat cramps, heat exhaustion and heat stroke.

If you do not have access to a cool-temperature location, visit one of the District’s cooled indoor facilities referred to above.

Symptoms of heat stroke:

Hot, dry skin (no sweating)

Hallucinations

Chills

Throbbing headache

High body temperature

Confusion/dizziness

Slurred speech

Groups at greatest risk for heat-related illness:

Infants

Children up to four years of age

People 65 years of age and older

People who are overweight

People who are ill or on certain medications.

Stay with News4 and NBCWashington.com for the latest on any heat-related advisories.

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