About 7:10 p.m. Thursday, when the rain was flying sideways in La Plata and the 60-mph wind was knocking down trees, a loudspeaker atop a telephone pole at the Charles County government center began to blare the tornado warning siren.

For those in downtown La Plata, the wailing alarm was clearly audible through the screeching wind, as was the recorded message that continually urged people to get off the streets and take cover.

"Do not delay!" the message said.

But the morning after the storm, some officials and residents said the warning signal should have taken its own advice and been activated earlier.

"It seemed like it was a little late when the siren was going off," said La Plata Mayor William F. Eckman. "It looked as if the storm had already pretty much passed."

The warning system, which is operated by the county's Emergency Services Department, was installed a little less than two years ago, after the deadly tornado that ripped through La Plata in April 2002. The siren is activated after the county receives notice from the National Weather Service forecast office in Sterling that a tornado could touch down in the area.

Initially after the tornado, the county indicated it planned to install up to 40 loudspeakers throughout Charles. Three other speakers have been purchased but not installed. Authorities said that at some point they will be put up in Clarks Run and at Kings Grant and near the town's sewage treatment plant.

"It's only one siren," Don McGuire, the county's director of emergency management said of the La Plata loudspeaker. "With that amount of wind, I'm not sure if it does that great of a job. You need to have them all working so they blast the area completely."

The storm that passed through Thursday evening caused little major damage in Southern Maryland. Many trees were knocked down, authorities said, in several cases bringing power lines down with them.

At the peak, 1,991 customers lost power in Southern Maryland, said Lea Sadler, a spokeswoman for the Southern Maryland Electric Cooperative. Charles had the most outages, with 1,500, in the Nanjemoy, Ripley and Indian Head areas. St. Mary's lost power in 456 homes in Hollywood, Mechanicsville, Valley Lee and Ridge. In Calvert, 35 lost power. By Friday afternoon, about 30 customers were still without power in Charles and St. Mary's.

Lightning bolts also sparked fires in several areas. In the Windward Key neighborhood of Chesapeake Beach, portions of a townhouse caught fire after a lightning strike. Bill Freesland, chief of the North Beach Volunteer Fire Department, said that half the circuit breakers in the house shorted out and the basement ceiling was burning; the blaze caused less than $10,000 in damage.

In St. Mary's County, lightning caused two house fires in California and Callaway and a shed fire in Medleys Neck, authorities said. Several roads across the region were closed temporarily by flooding or downed trees, including Franklin D. Roosevelt Boulevard in the Lexington Park area and Hawthorne Road in La Plata.

"We had a tremendous amount of trees down. And we did get a good amount of rain," Freesland said. "There was a flood warning out, but we didn't get hit with everything they were expecting."

The storm also caused a brief bit of drama at the courthouse in Prince Frederick. When power was knocked out in the building, a janitorial worker was trapped in an elevator, said Bobby Fenwick, the emergency management division chief in Calvert. Before long, the woman was rescued by the Prince Frederick Volunteer Fire Department, he said.

"It wasn't an exciting rescue," he said. "They just got her out of the elevator."