ST. GEORGE, Staten Island (WABC) -- Children playing with matches triggered a massive six-alarm fire on Staten Island Thursday that injured 21 people and destroyed seven homes, officials said.A house on Benzinger Avenue in St. George caught fire just after 6 p.m. and quickly spread to neighboring homes on both sides. With flames devouring her home, a woman ran to safety just as the fire department arrived."We had three buildings on fire, extremely heavy fire conditions. Extreme radiant heat on the street, enough that it melted siding on the buildings across the street," said FDNY Chief of Department James Leonard. "The fire eventually spread to seven buildings."A total of 42 individuals, 21 adults and 21 children, were left homeless and were being assisted by American Red Cross for temporary housing assistance.On Friday, FDNY fire officials said the blaze was started by two boys -- ages 6 and 8 -- playing with matches. According to the FDNY, the boys set papers on fire and threw them onto the porch, thinking they'd be OK there. But the fire quickly spread and engulfed the porch and home.The boys' mother was home but not directly supervising the boys at the time they set the fire, officials said. The mom is not going to be charged."It's a terrible, terrible accident," an FDNY official told Eyewitness News.The boys will be enrolled in the FDNY Juvenile Fire-Setters Intervention Program.Meanwhile, Melinda Wiegand is living out a nightmare after flames forced her and her four young children to flee for their lives from their Staten Island home.She received bags of clothes from a local church, but anything of value, any sentimental family treasures, are now gone.All of the injured were taken to Richmond University Medical Center.An MTA bus was en route to the staging area, at Jersey Street and Benziger Avenue.Seven buildings total were damaged. Two of them were totally destroyed and three others had moderate damage. Two others had minor damage.Between 40 and 50 houses were without power because firefighters had to cut it to the area while battling the fire. National Grid was requested to shut gas to affected structures."It was really hot and scary," said Jonathan, a resident who took cell phone video after he helped an elderly woman in his building get down the stairs and out to safety.The FDNY said that there was extreme radiant heat in the street, it was strong it melted the siding on buildings across the street.For much of the night, the smoke even on the street was so thick, it was difficult to see the firemen working above.About 250 firefighters and more than 60 apparatus responded to the fire."You can see they are big houses, on a hill. The firefighters did an unbelievable job," said Leonard. "On arrival, two minutes after three buildings on fire, they stopped that fire from spreading past that area. They did a really tremendous job with this fire."