Repair crews working through a hot day had reduced the number of District and Maryland homes and businesses without electricity late last night to slightly less than 2,400, Pepco officials said.

Pepco spokesman Robert Dobkin said air conditioning and refrigeration should be restored to most customers by this morning.

"We're making steady progress," he said.

But he said Pepco crews would "keep our fingers crossed" that new storms did not develop. That could keep repair crews inside and delay work, he said. Other problems, such as high temperatures predicted for today, could lead to new outages, he said.

The utility was dealing yesterday with additional calls as repairs to feeder lines exposed problems downstream and residents returned from weekend trips and reported that their electricity was off, too, he said.

The sudden, fast-moving and unusually violent storm that hit a string of neighborhoods along the Georgia Avenue corridor in the District and Maryland knocked out other services as well.

James Milhouse, 43, a federal employee who lives in a rowhouse a block from Georgia Avenue in Northwest Washington, pointed to a fallen tree that had severed the telephone line at the back of his house.

Milhouse said his wife, Bernadette, and children, Aniah, 5, and Bernard, 3, were awakened early Saturday by the pounding of hail on their windows, then by thunder and the crash of a tree across the street that damaged four homes.

The number of customers without power reached a peak of 55,000 of Pepco's 725,000 customers and was reduced to about 17,000 by the end of Saturday. The D.C. Department of Transportation received more than 100 calls about downed trees, and at least 20 intersections had malfunctioning traffic signals at the height of the area's power loss.

As of 10:30 p.m. yesterday, about 2,000 customers still lacked power in the District, about 300 in Montgomery County and 50 in Prince George's County, Dobkin said.

About 145 repair crews were on the job yesterday, he said.

Most Pepco crews have two to four members; there are a few single-person crews. The repair teams first tackled such dangerous situations as exposed power lines and power outages at hospitals, police, fire and 911 facilities. Then they worked on damaged substations and major feeder lines that served the most customers, Pepco officials said.

Yesterday, Pepco reminded customers of measures to take if storms this week lead to loss of power, including keeping away from flooded areas and staying indoors.

If power goes off, check for electrical damage inside the house, including frayed wires, sparks or the smell of burning insulation. Don't turn on the power after detecting such damage until an electrician has inspected the system and made necessary repairs. Staff writer Martin Weil contributed to this report.

Jim Walsh surveys the damage Saturday after a storm uprooted a large tree and swept it across his neighbors' house on Brunett Avenue in Silver Spring.