PHOTOGRAPHS -- Iris Carey, 4, was one of two sisters who died in the house explosion. (Photo courtesy of the Carey family) Violet Carey, 5, also died in the explosion. (Photo courtesy of the Carey family) Rescue workers rush a child pulled from the rubble to a waiting ambulance after a house collapsed in Hopkinton early this morning. (Staff photo by Bill Thompson) The top half of the house sits on Main Street following the explosion and collapse. (Staff photo by Bill Thompson) Fire Chief Gary Daughtery, left, and Massachusetts State Fire Marshal Stephen Coan, right, brief reporters at the scene. (Associated Press photo) Firefighters and rescue workers remained on the scene this morning. (Associated Press photo)

"They were the most loving little girls," said their grandmother Cindy Germain at the scene early this morning. "All they wanted to do was make cookies with me," she added in disbelief as firefighters worked to free the second of the girls from the wreckage.

Iris Carey, 4, and Violet Carey, 51/2, were killed in the explosion at 65 Main St., a four-family home in downtown Hopkinton. Their father, Heath Carey, crawled out of the wreckage and directed rescuers to his girls and wife.

"We cut a path to the children," said Hopkinton Fire Chief Gary Daugherty. "But there was nothing we could do."

One sister, her hair covered in gray soot, was pulled from the wreckage more than an hour after the 1:41 a.m. explosion. She was given mouth-to-mouth resuscitation by a rescuer as she was being rushed to an awaiting ambulance.

Rescue workers gathered around the child as she was gently handed over to medical personnel, her bare feet and arms never moving. Daugherty said she was suffering from cardiac arrest and was later pronounced dead at Milford-Whitinsville Hospital.

A firefighter among those who helped rush the unconscious child to the ambulance turned and grimly said, "We're doing the best we can."

The other sister was pinned under the debris, Daugherty said, and rescue workers worked into the dawn light to free her at about 6:30 a.m., after NStar could turn off the gas. Her injuries were fatal from the start, he added.

Firefighters and policemen at the scene paused and removed their hats and helmets for a moment of silence as the last little girl was removed from the house.

Rescue work was stopped twice during the early morning hours to shut off the gas line to the house and secure the splintered remnants of the building.

The girls' mother, Tara Carey, was carried out of the house soon after the blast by rescue workers, said Daugherty. Both parents were taken to Milford-Whitinsville Hospital where they were treated and released. Other residents of the house were also injured in the blast, none seriously.

The parents "thought it was the end of the world," Germain, the grandmother, said of the parents.

Daugherty said a gas leak is believed to be the cause of the explosion. He said one resident of the house called the fire dispatcher to report "a smell of gas."

The house exploded after the dispatcher hung up the phone, fire officials said. The shock shattered windows in houses and stores in downtown along Rte. 135. Even the fire station, located a few blocks away, sustained minor damage.

Firefighters and police rushed to the scene to help the building's 14 residents escape. Some, including a pregnant woman, were "walking wounded," needing immediate attention, Daugherty said. Others had to climb out of windows and gaps in the house, which was split open and blown out on all sides.

The force of the blast scattered sections of the house all over Rte. 135, forcing police to close it during the morning commute.

Jill Welch, who lives around the corner on Grove Street was watching CNN when her house was shaken by the explosion.

"I just heard a big eruption. I thought a tree fell on our house," Welch said. "I came outside and I could see a cloud of dust."

A neighbor who heard the blast watched the rescue.

"One woman walked out, one was carried out by a firefighter and a third they had to break the window to get her out," said the neighbor, Eric Montville, 19.

"We're trying to inch our way in carefully. We're worried about a secondary collapse," said Peter Chisholm, who acted as the public information officer at the scene under mutual aid from Ashland.

The State Police, Fire Marshal and Middlesex District Attorney's office also responded, along with NStar gas workers who worked furiously to shut off the gas line to the house. Firefighters from Holliston, Southborough, Ashland, Milford and Westborough, comprising the Massachusetts Southern Fire District Technical rescue team, were at the scene.

Fire crews carried heavy beams and used a jack to shore up the collapsing structure as they worked to search for people inside. There was no smoke or flame, only shattered pieces of the gray roof and yellow siding strewn in the street.

A group of teenagers anxiously watched the rescue, apparently looking for signs of a girl they know who lives at the house.

Despite the dozens of fire and rescue personnel working diligently to find those trapped, the area was eerily quiet. Main Street was lit by floodlights shining on the house, giving rescuers light to work with, and by the flashing from about a dozen fire engines, ambulances and police cars.

Rescuers abruptly pulled out of the house at about 3:15 when they suspected another gas explosion might be imminent. Crews frantically searched for a gas shutoff valve so that rescuers could resume looking for people believed to be still inside, including the child on the second floor.

An entire, intact portion of the house's roof was in the street, tipped up at one side by the remainder of a wall. Rte. 135 was expected to be impassable this morning in Hopkinton.

The front part of the house tore away from the back section, which stood seemingly undamaged. Furniture was visible inside the now-exposed rooms of the back section of the house.

The blast damaged windows on the Sovereign Bank two doors down, the house next door and the Star Package Store across the street.

The house was near the corner of routes 85 and 135, within sight of the Hopkinton firehouse and police station and within a couple of hundred yards of the Boston Marathon starting line.

One side of the yellow, three-story building crashed into a neighbor's house when it blew up.

"A loud explosion shook the house," said Valerie Banks, among the crowd of more than 100 people in shorts, T-shirts and pajamas watching rescue efforts. She and her husband Kenny live on Walcott Valley Drive, a condo complex near downtown.

"We thought it was a plane crash or train accident," she said.

"I live right over there and I felt as if my house came up and went back down. What an explosion!" said Barbara Tekut of Cedar Street.

"It's like something in a movie. What a nightmare."