The US Capitol police chief has told waiting reporters that they believed there was a child in the car involved in the incident and that he did not have any information on the person driving the car.
He said that multiple scene involved are now secure and said he had no information that the incident was related to terrorism and is anything other than an isolated incident.
More top news
New travel report looks at best value European city break destinations for UK tourists.
The bodies of two other crew members from the helicopter that crashed into the Atlantic over a week ago have yet to be recovered.
The man who sold himself to Americans as the ultimate deal-maker has had to back down over his planned healthcare reforms.