White House Locked Down Before President Obama Left for Selma

Vendor cart fire near North Lawn prompted lock-down, says Secret Service.

Washington, D.C, firefighters had contained the blaze at a vendor cart east of the North Lawn, said Secret Service officials. The first family was scheduled to leave the White House at 10:30 a.m. but left about an hour later than planned.

A K-9 also alerted Secret Service agents to a vehicle on 16th Street and Constitution Avenue, law enforcement officials said, but did not provide further details.