Scientists strongly suspect that an object about 2 miles wide smacked into the east coast off of Norfolk, VA about 35 million years ago. The splash probably reached about 30 miles high and tsunamis may have reached the base of the Blue Ridge Mountains west of Washington, DC, and sea bed sediments were likely ignited for a time.
The force released was probably greater than all warheads in the cold war nuclear arsenals of the former Soviet Union and the United States Combined. Get the details
here.