Two more children died Tuesday morning of wounds from the shootings at an Amish schoolhouse, raising the death toll to five girls plus the gunman who apparently was spurred by a two-decades-old grudge.
The toll from the nation's third deadly school shooting in less than a week rose twice within a matter of hours Tuesday with the deaths of a 9-year-old girl at Christiana Hospital in Delaware and a 7-year-old girl at Penn State Children's Hospital in Hershey.
Five additional girls were hospitalized.
The Bush administration on Monday called for a school violence summit to be held next week with education and law enforcement officials to discuss possible federal action to help communities prevent violence and deal with its aftermath.
State police spokeswoman Linette Quinn said the two girls who died early Tuesday had suffered "very severe injuries, but the other ones are coming along very well."
The 9-year-old girl died about 1 a.m., and the 7-year-old girl died about 4:30 a.m.
"Her parents were with her," hospital spokeswoman Amy Buehler Stranges said of the 7-year-old. "She was taken off life support and she passed away shortly after."
Authorities said the gunman, Charles Carl Roberts IV, 32, wrote what authorities described as suicide notes, took guns and ammunition and went to a nearby one-room schoolhouse, where he opened fire on several girls and took his own life, authorities said.
Roberts, a father of three from nearby Bart Township and was not Amish, did not appear to be targeting the Amish and apparently chose the school because he was bent on killing young girls as a way of "acting out in revenge for something that happened 20 years ago," said state police Commissioner Jeffrey B. Miller.
"This is a horrendous, horrific incident for the Amish community. They're solid citizens in the community. They're good people. They don't deserve ... no one deserves this," Miller said.
The names of the dead were not immediately released.
Of the injured, a 6-year-old girl remained in critical condition and a 13-year-old girl was in serious condition at Penn State Children's Hospital, spokeswoman Buehler Stranges said. She said the names of the children were not being released.
Three girls, ages 8, 10 and 12, were flown to Children's Hospital of Philadelphia, where they were out of surgery but remained in critical condition, spokeswoman Peggy Flynn said.
Roberts brought with him supplies necessary for a lengthy siege, including three guns, a stun gun, two knives, a pile of wood and a bag with 600 rounds of ammunition, police said. He also had a change of clothing, toilet paper, bolts and hardware and rolls of clear tape.
He released about 15 boys, a pregnant woman and three women with infants, barred the doors with desks and wood and secured them with nails, bolts and flexible plastic ties. He then made the girls line up along a blackboard and tied their feet together.
The teacher and another adult fled to a nearby farmhouse, and authorities were called at about 10:30 a.m. Miller said Roberts apparently called his wife from a cell phone at around 11 a.m., saying he was taking revenge for an old grudge. Miller declined to say what the grudge could have been.
"It seems as though he wanted to attack young, female victims," Miller said.
Miller told NBC's "Today" that Roberts lost a daughter "approximately three years ago" and that that may have been a factor in the shooting.
He said a teacher had to run to a farm house to call police because there wasn't one at the school, in keeping with Amish custom.
Parents refused to fly in planes — again in keeping with Amish tradition — and had to be driven to see their children at hospitals, Miller told "Today." Some were taken to the wrong hospitals in the confusion, Miller said.
From the suicide notes and telephone calls, it was clear Roberts was "angry at life, he was angry at God," and co-workers said his mood had darkened in recent days, Miller said.
In a statement released to reporters, the gunman's wife, Marie Roberts, called her husband "loving, supportive and thoughtful."
"He was an exceptional father," she said. "He took the kids to soccer practice and games, played ball in the backyard and took our 7-year-old daughter shopping. He never said no when I asked him to change a diaper."
"Our hearts are broken, our lives are shattered, and we grieve for the innocence and lives that were lost today," she said. "Above all, please pray for the families who lost children and please pray too for our family and children."
The attack bore similarities to a deadly school shooting last week in Bailey, Colo., but Miller said he believed the Pennsylvania attack was not a copycat crime. "I really believe this was about this individual and what was going on inside his head," he said.
On Friday, a school principal was shot to death in Cazenovia, Wis. A 15-year-old student, described as upset over a reprimand, was charged with murder.