Saturday's flooding also hit North Baltimore, where Sunday morning, cars near Meadow Mill were stacked atop one another after being moved by rising water the night before. People were trapped in partially submerged vehicles along Interstate 83 Saturday night, police said. The National Weather Service issued flash flood and severe thunderstorm warnings Saturday night for Baltimore City, and parts of Baltimore, Anne Arundel, Carroll, Frederick, Howard and Montgomery counties. The agency also warned of the possibility of 60 mph wind gusts that could knock down trees and branches, damaging property and blocking roads. Baltimore Gas and Electric Co. reported nearly 80 power outages in the Baltimore region, affecting more than 4,000 people. And a number of roadways were closed. Elise Armacost, spokeswoman for Baltimore County police and fire, said first responders undertook a "significant number" of water rescues as "extremely heavy rain" fell in the western part of the county. One driver and a passenger waited on the roof of a submerged car on Frederick Road until rescued. In Baltimore, police worked with the fire and city transportation departments to rescue drivers in standing water. Police spokesman Donny Moses warned residents that if they see standing water, it's likely too deep to drive through. "People who decide to take chances not only put themselves at risk, but also the people who rescue them in danger," he said. "That's what we do gladly, but you got to consider more than just yourself. Safety is for everyone." Howard County's Fire Department also was out in force, rescuing stranded drivers and residents with assistance from the Sykesville-Freedom District Fire Department and Lutherville Volunteer Fire Department. At 11:59 p.m., county executive Alan Kittleman declared a state of emergency for Howard County, he said on Twitter. Denise Weist, spokeswoman for Howard County fire, said that a number of cars were carried off roads by flooding in Ellicott City. She advised people to stay off the roads and pay attention to signs. Officials reminded residents that as little as 6 inches of water can be dangerous on the road. Becca Souder, 27, of Catonsville was stranded with her husband, Dereck, 36, in Cacao Lane Restaurant on Main Street in historic Ellicott City. She was celebrating her birthday. "There is probably about 20 of us standing at the highest level of the restaurant," Souder said. "The middle floor is not 100 percent flooded, but the bottom floor is completely flooded." Cars were "literally floating down the road, like bobbing when you go fishing," she said, adding that waters had broken the windows of a nearby restaurant, carrying its tables and chairs down the street. "Water started coming in like a waterfall," she said, "inch by inch." That's when restaurant employees moved them to the second floor, and then to the third floor. The fire department responded about 9:30 p.m. and evacuated people from restaurants to the top of a nearby hill, she said. The flood waters later subsided, revealing collapsed sidewalks. Courtney Watson, a former Howard County council member, is already thinking ahead. Watson and other residents took to social media to organize a donation of supplies - rubber gloves, buckets, shovels, bleach and sponges - to shop owners affected by the floods. Motorists reported deep waters in roads around the region. Interstate 83 between Falls Road and Cold Spring was closed because of flooding, as was Interstate 695 at Exit 16 (I-70). Howard County fire department officials reported severe flooding on Main Street, Howard Road, St. Johns Lane and Route 70 at Route 29.