FirstLoveMovies

After their father is killed, three siblings vow to track down the beast reponsible, which they believe is a werewolf, and are soon joined in their vendetta by a man who runs a cable television station and some kids, roughly fourteen to eighteen, who hang out with him. Yet, when the creature learns they are onto him, he traps them inside a building and states no one will leave alive. A low budget horror flick.

http://www.imdb.com/title/tt0200963/