Now Playing: Parkland activists launch new push for youth voter turnout: 'We can fix the system'

Now Playing: Puerto Rico residents recovering from Maria brace for hurricane season

Now Playing: Simon Cowell says he hasn't used his phone in 10 months

Now Playing: New book explores the murder case that propelled Abraham Lincoln to presidency

Now Playing: Owner says Delta tried to 'cover up' dog's death

Now Playing: Manhunt underway after murder spree in Arizona

Now Playing: FBI agent's gun fires on dance floor

Now Playing: Warriors score 2nd victory over Cavs in NBA Finals

Now Playing: Toddler, 3, makes life-saving 911 call after mother collapses

Now Playing: Facebook mired in new privacy scandal

Now Playing: Flooding, fires hit East and West coasts

Now Playing: Weekend Rewind: Giuliani's tension with special counsel

Now Playing: New toys inspired by the movies

Now Playing: #FoodJenga is the newest way to stay entertained at dinner

Now Playing: Police in Phoenix continue to search for a killer on the loose

Now Playing: Severe weather threats continue to affect thousands of people across the country

Now Playing: An FBI agent's gun accidentally discharged in a Denver nightclub

Now Playing: Victims of the Marjorie Stoneman Douglas School shooting receive posthumous degrees

Now Playing: A toddler was rushed to the emergency room after an allergic reaction to sunscreen

Now Playing: New details on the woman who drove through a little league game in Maine