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
Now Playing: American citizen and his wife freed from captivity in Venezuela
Now Playing: USC’s president steps down after sexual assault allegations against campus doctor
Now Playing: Hero science teacher takes bullet for his students
Now Playing: Property taxes spike, shocking homeowners nationwide
Now Playing: Raging fire at landfill outside Portland
Now Playing: Donor recipient receives new heart after six-year wait
Now Playing: Heroic teacher tackled middle-school shooter after running toward bullets
Now Playing: Airline passenger arrested after alleged midair tirade over alcohol
Now Playing: Grandparents convicted of kidnapping in international custody case
Now Playing: Detailed account of how hero teacher took down alleged Indiana school shooter
Now Playing: Hospital staff finds way for patient to watch his twins graduate from high school
Now Playing: 2 bystanders killed gunman firing on crowded restaurantgoers: Police
Now Playing: In 3 weeks, lava has smothered more than 2,000 acres of Hawaii’s Big Island
Now Playing: Plane passenger faces federal charges after brawl breaks out over beer
