Now Playing: Queen Elizabeth's Baby Pictures: The Little Girl Who Would Be Queen

Now Playing: Inside the Secret Life of Queen Elizabeth

Now Playing: Tips to find the best mobile data plan

Now Playing: Backlash over Instagram post by wife of treasury secretary

Now Playing: Flash flooding hits the heartland

Now Playing: Second largest Powerball jackpot in history

Now Playing: Tens of thousands of protesters expected at Trump's Phoenix rally

Now Playing: Identities not yet revealed of bodies found on U.S.S. McCain

Now Playing: 42 injured in Philadelphia commuter train crash

Now Playing: Trump's strategy on the war in Afghanistan

Now Playing: Solar eclipse brings Americans together

Now Playing: Shootout at an Ohio courthouse

Now Playing: Deadly earthquake rattles Italian resort island

Now Playing: Trump reveals new Afghanistan strategy

Now Playing: The effects of the total eclipse

Now Playing: The Great American Eclipse sweeps across the US

Now Playing: Another violent collision involving a Navy destroyer

Now Playing: Passenger attempts to open cabin door mid-flight

Now Playing: Firefighters and lifeguards form human chain to rescue swimmer

Now Playing: Sentencing in multi-million dollar lottery scheme