Fire crews feared a roof was going to collapse when they were fighting a house fire in Surprise on Thursday afternoon. The firefighters were called out to the home near Bell and El Mirage roads around 2:30 p.m. Crews were going with an "offensive" strategy but when the roof started to sag, they pulled out and went defensive. "That means we're going to fight the fire from the outside," said Julie Moore with the Surprise Fire-Medical Department. But there was concern the flames might damage neighboring houses. "There's a great exposure danger so we upgraded our response to a 'first alarm.' That means were going to have about 50 firefighters battle this fire," said Moore. Aerial video shows the roof did collapse and there is a huge hole in the house. No other houses were damaged.