From a story on axios.com by Rebecca Falconer headlined “Sonic boom in D.C. as F-16 fighter aircraft move to intercept Cessna”:

A sonic boom rang out across the D.C. region as authorities responded to an unresponsive pilot flying a Cessna that prompted officials to place the U.S. Capitol complex on alert on Sunday afternoon.

State of play: North American Aerospace Defense Command (NORAD) said it deployed F-16 fighter aircraft to intercept the plane that later crashed. Officials in Maryland said the boom was caused by an authorized Defense Department plane out of Joint Base Andrews.