Three people are dead after a gunman entered a Sydney, Australia chocolate shop taking the 17 people hostage. The siege lasted 16 hours, ending when police stormed the building after hearing gunfire. The victims: two of the hostages, a 34-year-old man and a 38-year-old woman. The gunman was also killed.

It's the latest in a string of lone wolf terror attacks in major world cities this year. Officials now fear it could happen in the U.S.

Deborah Feyerick is OutFront from New York City.