The barking of their 5-year-old boxer awakened Gus and Denise Hatzis just before 3 a.m Saturday.
Gus went downstairs to see what was wrong.
A wall in the attached garage was sagging and he moved the family cars.
Moments later, the snow-covered roof of the garage collapsed.
Newsday reports the family had to leave the house over concerns about more structural damage.