Now Playing: Volcanic eruption on the big island of Hawaii

Now Playing: Wyatt Russell dishes on Captain America, Falcon and the Winter Soldier

Now Playing: All Americans 16 and older are eligible for COVID-19 vaccines

Now Playing: Prince Harry prepares to return to LA after funeral

Now Playing: Former deputy under arrest for killing 3 people in Austin

Now Playing: Massive migrant center closed in Houston

Now Playing: Jury deliberates Chauvin case in death of George Floyd

Now Playing: Garland discusses domestic terror, gun violence and voting rights

Now Playing: Learn from two NASA engineers about how they sent both a rover and helicopter to Mars

Now Playing: The Death of George Floyd: Jury begins deliberations in Derek Chauvin's trial

Now Playing: Robin Thicke sings ‘Look Easy’ on ‘GMA3’

Now Playing: 3 must-know yoga moves to refresh yourself

Now Playing: ‘Grey’s Anatomy’ star Jesse Williams wants you to ‘BeGreat’

Now Playing: Should you get COVID-19 vaccine if you’ve had a bad reaction to other vaccines?

Now Playing: Oklahoma City bombing survivor’s ‘impossible transformation’

Now Playing: Sen. Hirono’s anti-Asian hate bill gaining momentum

Now Playing: Prosecution and defense present closing arguments in Derek Chauvin trial

Now Playing: Mom who survived a COVID pregnancy celebrates her daughter’s first birthday

Now Playing: Key moments from Derek Chauvin trial

Now Playing: Teen battling bone cancer surprised with "pet" dragon