Now Playing: 12-year-old girl abducted at Reagan National Airport found safe

Now Playing: Family thanks heroes who rushed to save kids from burning building

Now Playing: Oppressive conditions leave 29 states under heat warning

Now Playing: Bear attacks worker at a wildlife resort in Pennsylvania

Now Playing: Blistering heatwave scorching much of the U.S.

Now Playing: Missing 2-year-old Minnesota boy drove himself to county fair on toy tractor

Now Playing: Doorbell camera captures moment of deadly Southern California blast

Now Playing: 'Storm Area 51' creator urges followers not to rush military base

Now Playing: Employees quit store in protest of alleged racism

Now Playing: Softball strike knocks phone to ground

Now Playing: Neil Armstrong was the 1st man to walk on the moon 50 years ago today

Now Playing: Philadelphia man scales apartment building on fire

Now Playing: American woman, Australian boyfriend killed during road trip in Canada

Now Playing: Trump says Rep. Ilhan Omar is 'lucky to be where she is'

Now Playing: US intensifies air patrols over the Strait of Hormuz

Now Playing: Heat index could reach as high as 115 degrees

Now Playing: Yankees manager suspended for 1 game, fined after tantrum during game

Now Playing: Man spotted scaling 19-story burning apartment building in Philadelphia

Now Playing: 'Treasure' found during Apollo 11 Mission Control restoration

Now Playing: Police investigating after couple found dead on remote highway