Roaring Thunder vets rumble through Washington Thousands of US military veterans, adorned in tattoos, leather and American flags, roared through Washington Sunday on the annual Rolling Thunder motorcycle parade to honor America's. The Memorial Day weekend event, originally started by Vietnam War veterans seeking the return of the remains of prisoners of war (POWs) and those missing in action (MIAs), now includes veterans of more recent conflicts including Iraq and Afghanistan. Images and soundbites.