NEW HAVEN, Conn. — A Connecticut fire investigator says a gasoline-fueled arson blaze spread "in a very rapid, quick and violent manner" through a house where a mother and two girls died in a 2007 home invasion.

Paul Makuc testified today in the trial of Steven Hayes, one of two men charged in the killings of Jennifer Hawke-Petit and her daughters, 17-year-old Hayley and 11-year-old Michaela. Prosecutors say Hawke-Petit was strangled and her daughters died of smoke inhalation. Hawke-Petit attended elementary school in Slippery Rock and her parents still live in Slippery Rock.

Makuc says the fire began in a family room where the mother's body was found and quickly spread to the second floor into the girls' bedrooms.

Prosecutors say Hayes and co-defendant Joshua Komisarjevsky tied the girls to their beds and poured gas on or around them before burning the family's Cheshire house.