A pedestrian was killed crossing Atlantic Avenue Thursday after being struck by what police sources say was a Secret Service vehicle.

Witnesses say that Maria Tripp was crossing Atlantic Avenue with her nephew and daughter when she was hit by a Chevy Impala. Police sources say that the driver struck her with such velocity that the vehicle wound up hitting the curb and blew out its tires.

Police say the driver stayed at the scene, and they do not expect any charges to be filed. The victim's daughter and nephew were not injured.