UPDATE: Wednesday – 3/26/2014, 3:43pm ET

WASHINGTON – Police found no dangerous materials at the National Air and Space Museum and have left the building.

All streets have been reopened and the building is now open to visitors.

EARLIER: Wednesday – 3/26/2014, 3:06pm ET

WASHINGTON – The Smithsonian’s National Air and Space Museum has been evacuated after police received a call about a suspicious package.

A spokesman for D.C. police says a man passed out next to a briefcase.

Police are still on scene investigating what happened.

The man has been transported to a local hospital.

Smithsonian spokeswoman Becky Haberacker tells The Associated Press that all visitors and staff were evacuated onto the National Mall about 12:45 p.m. Wednesday. She says streets on both sides of the museum were closed.

It was not immediately clear how long the museum would be evacuated.

Stay with WTOP for updates on this developing story.

The Associated Press contributed to this report. Follow @WTOP on Twitter and on Facebook.