Severe thunderstorms caused downed trees, collapsed roofs and flash flooding damage in the Philadelphia region on Saturday. Videos coming into NBC10 show the extent of damage caused by the strong thunderstorms that swept through the region Saturday afternoon. In the area of 55th and Vine st reets in West Philadelphia, a roof at least partially blew off a Philadelphia Housing Authority apartment building. NBC10’s Kelsey Kushner was on the scene to find the roof, along with other debris, on the street. At least four cars were damaged, and dozens of residents of the building were evacuated. Officials said the building suffered water damage along with the roof coming off, and 11 units have been impacted. The residents have been taken to hotels for about a week. Mayor Cherelle Parker and other Philadelphia leaders began holding a press conference at the location at around 8:15 p.m. The event is being livestreamed in this article. A vacant building also partially collapsed at S. 24th Street near Washington Avenue in Southwest Center City. NBC10 was on scene to find that bricks and other debris had fallen on a Jeep. No injuries have been reported. Ayhan Yuksal, the owner of the vacant building, said that the building has been empty for 20 years and he planned to make apartments at the site. A building collapse at the 5600 block of Lansdowne Avenue also damaged cars and filled the street with bricks. Carroll Park in West Philadelphia was also severely damaged, with several trees downed. Several other videos shared with NBC10 showed downed trees on cars and other damage on Saturday. Tree down at 43rd and Locust streets Another angle of tree down at 43rd and Locust streets in West Philadelphia. A large tree or several trees also fell in front of a home at Market and Millbourne streets in Upper Darby. In Lower Merion Township, a state of emergency was declared due to downed trees and wires, and officials urged people to stay off the roads. NBC10 was in Lower Merion to find damage from several trees down, including more than one tree down on one property. SEPTA is also telling riders there are currently systemwide delays or cancelations due to the storms. And, more than 33,000 PECO customers were without power as of 7:12 p.m., according to its outage tracker. According to our NBC10 First Alert Meteorology Team, the threat of flash flooding has ended, and the rest of the weekend will be mostly nice and dry. This is a developing story; check back for more details. This story uses functionality that may not work in our app. Click here to open the story in your web browser. ...read more read less