Now Playing: World's largest active volcano sets off warning signals in Hawaii

Now Playing: Dad goes viral for his simple tips to reduce ‘mental load’ for his partner

Now Playing: Rapper Taxstone convicted of shooting bodyguard during New York concert

Now Playing: Chef Robert Irvine talks 'Restaurant Impossible'

Now Playing: ABC News Live: Biden, Trudeau reach deal to reduce migration at northern border

Now Playing: Utah passes laws aimed at restricting child and teen access to social media platforms

Now Playing: Chicago residents concerned after 2 women found dead, teen missing

Now Playing: Lawmakers skeptical about TikTok CEO’s responses on safety, spying concerns

Now Playing: US stocks drop as concerns grow over Germany’s Deustche Bank

Now Playing: ABC News Live: US retaliates after Iran-backed groups attack Americans in Syria

Now Playing: Gwyneth Paltrow expected to testify in 2016 skiing accident case

Now Playing: ABC News Live: US launches retaliatory airstrikes in Syria

Now Playing: Formerly conjoined twin goes home 2 months after surgery

Now Playing: Hyundai and Kia recall vehicles over fire concerns

Now Playing: Biden seals new deal to divert asylum seekers crossing into Canada

Now Playing: TikTok CEO faces bipartisan grilling from Capitol Hill lawmakers

Now Playing: Transgender athletes banned from elite international track and field events

Now Playing: CDC issues warning about contaminated eye drops after infections, 3 deaths

Now Playing: Police release body camera footage of fatal shooting of man chased for shoplifting

Now Playing: 30 million on alert for tornadoes, flooding, damaging winds