Mormon sisters Ali and Christina Christensen are scheduled to sing tonight in the finals for NBC's "America's Got Talent."
The LDS sisters from Idaho Falls, Idaho, made the Top 10 in the show where the prize is $1 million and headlining their own Las Vegas show.
The winner is determined by voting via text message, phone calls and online for a couple of hours after the show airs. The winner will be announced during the show Wednesday, Sept. 8.
Ali, 20, and Christina, 13, both have cystic fibrosis and were told early in life they would never sing in public because the disease would restrict their breathing. Their sister passed away last summer.
They will be competing against nine other acts for the top prize, including two male singers, a dance crew, an extreme cyclist, a fraternity of blacklight dancers, a magician, a pair of ballroom dancers and opera singers.