Now Playing: House GOP: ‘No evidence’ Trump campaign ‘colluded’ in Russia investigation
Now Playing: Leaders from North, South Korea vow to sign peace treaty to end war
Now Playing: Prince William and Duchess Kate release name of new baby boy
Now Playing: North, South Korea agree to end war
Now Playing: What is May Day?
Now Playing: Prince William, Princess Kate reveal son’s name
Now Playing: North Korea, South Korea agree to end war
Now Playing: Korean leaders plant ‘peace tree’
Now Playing: North and South Korean leaders meet in historic summit
Now Playing: North Korea’s Kim Jong Un crosses DMZ line for historic meeting with South Korea
Now Playing: Prince Harry picks Prince William as best man
Now Playing: Son of US detainee in North Korea stays hopeful amid anticipation of Trump-Kim talk
Now Playing: 2 brothers rescued after spending 21 hours at sea without food or water
Now Playing: Danish inventor found guilty of killing Swedish journalist
Now Playing: South Korean residents of the DMZ look forward to inter-Korean summit
Now Playing: New details about suspect in deadly Toronto attack
Now Playing: French president urges the US to stay in the Iran nuclear deal
Now Playing: Victims of van ‘attack’ predominantly women: Police
Now Playing: 1st statue of woman on London’s Parliament Square unveiled
Now Playing: Partially blind and deaf dog rescues lost girl
