Six families were left out in the cold after a five-alarm fire tore through two buildings and a day care center in Union City Saturday.

The fire started just before 11 p.m. Firefighters from North Hudson Regional Fire and Rescue, Bayonne, Hoboken and Jersey City battled the 30-foot flames for at least four hours.

Fire officials say the cold weather froze fire hydrants, which complicated the mission. They say they don?t know the cause of the fire or where it started, but may know more once they do a complete walkthrough.

The buildings were so badly burnt, officials say they will have to be demolished.