WASHINGTON—Five workers were injured Thursday when a building under construction collapsed in the nation’s capital, trapping one man for more than an hour as firefighters worked feverishly to free him from layers of debris. The collapse happened around 3:30 p.m. in the Brightwood Park neighborhood of Washington. Fire officials said the five-story building was under construction when it fully collapsed, injuring all the workers at the site. Firefighters worked for more than 90 minutes to free one man man from the rubble, using saws and other equipment to cut through wood and other debris that trapped him. District of Columbia Fire and EMS Chief John Donnelly said four other construction workers were pulled out of the rubble after rescuers arrived at the scene and they were all taken to the hospital with non-life-threatening injuries. The man who was trapped was first found by a search and rescue dog and was …