Now Playing: American woman in ISIS wants to come home

Now Playing: A lion yawns, sparkles fly, monks pray

Now Playing: This day in history: Feb. 22, 2014

Now Playing: News headlines today: Feb. 19, 2019

Now Playing: Across the pond: ISIS brides, UK lawmakers and Facebook

Now Playing: Woman saved after getting trapped in mud

Now Playing: Firefighters make daring rescue

Now Playing: ISIS' last stand in Syria

Now Playing: The Venice Carnival, Nigerian elections, anniversary of Libya's revolution

Now Playing: Gondolas wind through Venice for carnival

Now Playing: Cat welcomes passengers to train station

Now Playing: Sediment floods Great Barrier Reef

Now Playing: Westminster dogs, Northern Lights and the Year of the Pig: World in Photos

Now Playing: Brexit 'prepper' stockpiling supplies in case of a doomsday 'no-deal'

Now Playing: Vice President on last leg of Poland trip, visits Auschwitz concentration camp

Now Playing: Mike Pence calls out European nations for not withdrawing from Iran nuclear deal

Now Playing: World View: Inside a Syrian refugee camp, tensions rise in Venezuela and more

Now Playing: Across the Pond: Unrest in Haiti, climate strike, royal Valentine's Day

Now Playing: Polar bear cub gets her first checkup

Now Playing: Final push made on remaining ISIS stronghold in Syria