Sen. Jeff Merkley heard a "pow" on Thursday and, for an instant, thought it was the sound of cars driving over steel plates. He looked up and saw a swarm of police cars on the grounds outside the U.S. Capitol.
That's odd, thought the Oregon Democrat. Too many police cars for an ordinary march or demonstration.
Within seconds, the sound was repeated, "pow-pow-pow," and a Capitol police officer screamed at Merkley and two other senators to get down and take cover.
Merkley realized it was gunfire as they hid behind a car.
A few hundred yards away, a woman driving a black Infiniti was stopped after a police chase. Minutes earlier, she had tried to ram through a White House barricade.
"At that point, many, many police cars started storming up Constitution Avenue from west to east, and I'm looking around, wondering what's going on," Merkley said in a telephone interview with The Associated Press.
Merkley said he had never been told what to do in such a situation. When the shooting stopped, he and Sens. Sherrod Brown of Ohio and Bob Casey of Pennsylvania ran back to the building. They struggled to get the doors open.
"You had five or six senators waiting to re-enter the Capitol, fussing about how to get the door open," Merkley said.
Inside, television screens warned people to stay away from windows. Merkley said he spoke to his wife and mother then returned to his office.
Capitol Police Chief Kim Dine said the driver of the Infiniti had died after being shot by police.
Senate Sergeant at Arms Terrance Gainer said a child was taken from the car to a hospital. A police officer was injured in the traffic accident, but Gainer said the injuries were not life-threatening.
The shooting came two weeks after a mentally disturbed employee terrorized a Navy Yard with a shotgun, leaving 13 people dead including the gunman.
On Twitter, three Oregon congressmen sent out messages indicating they were safe along with their staffs.
"Thank you to the Capitol Police for their service & bravery today and every day," tweeted Rep. Greg Walden. "Prayers for those who are injured. My staff and I are safe."
Thank you to the Capitol Police for their service & bravery today and every day. Prayers for those who are injured. My staff and I are safe.Rep. Greg Walden (@repgregwalden) October 3, 2013
There are reports that shots were fired on Capitol Hill. All of my staff is safe and accounted for. We are on lockdown in my office.Rep. Kurt Schrader (@RepSchrader) October 3, 2013
Office locked down with everyone else. To friends and family, everyone accounted for and secure.Earl Blumenauer (@repblumenauer) October 3, 2013
Reach reporter Nigel Duara on Twitter at http://www.twitter.com/nigelduara