Now Playing: Man with ax kills 1 after driving into people in San Francisco: Officials

Now Playing: Father plows car into restaurant, kills daughter

Now Playing: Subtropical storm Alberto expected to make landfall tomorrow

Now Playing: Former President George H.W. Bush hospitalized in Maine

Now Playing: Man makes dangerous getaway in his car

Now Playing: Border Patrol changes story about agent who shot and killed immigrant

Now Playing: Lava from the Kilauea volcano can be seen from space

Now Playing: Flames shoot out from car on the highway

Now Playing: Policeman punches young woman in the head on the Jersey Shore

Now Playing: McCain has an important message for Americans

Now Playing: High school valedictorian addresses grads through bullhorn following speech ban

Now Playing: This Memorial Day weekend, honoring those who lost their lives in non-combat accidents

Now Playing: New details about North Korea meeting with South Korea

Now Playing: Hero saves highway driver from car on fire

Now Playing: Border Patrol agent accused of shooting and killing woman in Texas

Now Playing: American held in Venezuelan prison returns to US

Now Playing: Changing wind pattern raise fears of dangerous toxic gases in Hawaii

Now Playing: Gulf Coast braces for Alberto as storm threatens to ruin holiday weekend

Now Playing: Subtropical Storm Alberto is picking up speed and getting stronger

Now Playing: 20-year-old woman shot and killed by border patrol agent in Texas