( CNN ) -- A fire at a house in Connecticut early Christmas morning killed two adults and three children , fire officials said . Two other people made it out alive . `` It is a terrible , terrible day for the city of Stamford , '' said Mayor Michael Pavia , briefing reporters about the `` horrible tragedy . '' `` There probably has not been a worse Christmas Day in the city of Stamford , '' he said . Multiple calls came in shortly before 5 a.m. , fire officials said . The first firefighters on the scene attempted rescues within the home , but `` were pushed back by intense flame and heat , '' said Acting Fire Chief Antonio Conte . The cause remains under investigation . Due to the condition of the building , it will be days before investigators can determine what happened , Conte said . Seven people lived in the house , Conte said . He had no immediate information on their identities or the conditions of the two who came out alive and were taken to the hospital . The home is in Stamford 's Shippan Point neighborhood , just in from the Long Island Sound , fire officials said . CNN 's Josh Levs contributed to this report .
NEW : two people made it out alive , officials say . NEW : Connecticut Mayor Conte says Stamford has probably never had a worse days . NEW : It will be Christmas Day before investigators can determine what happened , a fire official says .