U.S. Capitol Police and the D.C. Fire and EMS Department didn’t find any signs of a fire, Lt. Kimberly Schneider of the U.S. Capitol Police said.
The visitor center is located underneath the plaza between the U.S. Capitol and 1st Street.
The office of the U.S. Senate Sergeant at Arms tweeted about 9:30 a.m. that “staff should respond to assigned assembly areas.” By 10:30 a.m., staff and visitors could return to the building.
First Street, between Constitution Avenue NE and Independence Avenue SE, and East Capitol Street, between 1st and 2nd streets, were closed temporarily as authorities investigated the alarm.
Photo via Wikimedia/Fletcher6