President Obama and family were preparing to depart for Selma, Alabama when a loud noise was heard, which prompted a lock down of the White House. There is also a fire in the area:

In addition to the “loud noise” there’s also this:

Early reports say the fire came from a vending truck:

Updates:

CBS News’ White House Correspondent Mark Knoller and ABC report:

It’s unknown if the vehicle that attracted the Secret Service’s attention is the same that caught fire.