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Two New York firefighters who survived a calculated ambush that killed two fellow firefighters and wounded several others in suburban Rochester, N.Y. say they are thankful for the support they've received from the public.

Volunteer firefighters Joseph Hofstetter and Theodore Scardino, who had been in guarded condition in the hospital, were upgraded to satisfactory condition on Wednesday.

Strong Memorial Hospital in Rochester released a statement from the two saying they were "humbled and a bit overwhelmed by the outpouring of well wishes for us and our families.

The firefighters said their "thoughts and prayers" were with the families of colleagues Michael Chiapperini and Tomasz Kaczowka, killed by William Spengler Jr., a convicted felon barred from having guns. Funerals are set for the next few days for Chiapperini and Kaczowka.

Spengler mapped out a plan and left behind a note outlining his "clear intent" to burn his neighborhood to the ground and "do what I like doing best, killing people," authorities said.

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The gunman set his home and a car on fire on Monday in what police called "a clear ambush on first responders." Spengler was found dead at the scene.

The two to three page note contained the shooter's "clear intent" to ambush first responders but did not reveal the shooter's motive. The police chief said that the shooter's motive may have taken root more than 30 years ago when the police department arrested Spengler for murdering his grandmother.

"There was no motive in the note. There were some ramblings in there. It spoke mainly of his intent to burn his neighborhood down and hurt as many people as possible before stopping," Webster police Chief Gerald Pickering said at a press conference on Tuesday morning.

Hours later, authorities announced that human remains were found in the charred house that 62-year-old Spengler shared with his 67-year-old sister, Cheryl Spengler. Police said the victim is believed to be the shooter's sister.

Police say Spengler armed himself with a revolver, shotgun and military-style rifle before he set his house afire to lure first responders into a pre-dawn death trap on Christmas Eve.

Pickering says Spengler "was equipped to go to war."

Spengler killed himself as seven houses burned around him. A friend said Spengler hated his sister but police say a motive hasn't been determined.

Spengler was armed with a .223-caliber Bushmaster rifle, a .38-caliber revolver and a 12-gauge shotgun, cops said. The Bushmaster rifle used by Spengler is the same make and caliber semiautomatic rifle as the one used in the Connecticut school massacre.

Spengler killed two firefighters and wounded two others before fatally shooting himself. Once firefighters arrived, Spengler, under a  'position of cover' fired at the firefighters from a distance after they arrived around 5:30 a.m. to battle the blaze near the Lake Ontario shore, just east of Rochester, Town of Webster Police Chief Gerald Pickering said.

The shooter was found dead hours after a brief shootout with cops according to Pickering. Spengler was found around 11 a.m. near the shore of the lake with a self -inflicted gun shot wound. The first Webster police officer who arrived on the scene exchanged gunfire with the shooter.

Pickering said there were "heroic acts" by first responders who attempted to bring their comrades under cover from the attack.

"It appears to be a trap that was set for responders," Pickering said in a press conference on Monday.

"It is a very difficult situation," he said Monday at a press conference, holding back tears. "People get up in the middle of the night to fight fires.They don't expect to be shot and killed."

Of the four volunteer firefighters, two were fatally shot including Kaczowka and Chiapperini, who was also a lieutenant and public information officer for the local police department.

The two volunteers who survived were taken to University of Rochester Medical Center were they were listed in guarded condition in the intensive care unit, according to hospital officials. Hofsetter suffered server injuries to his pelvis, while Scardino was shot in his shoulder and lung. Both men are stable.

The West Webster Fire District received a report of a car and house on fire on Lake Road, on a narrow peninsula where Irondequoit Bay meets Lake Ontario, Flynn said.

"When they got there, they stated to take on rounds and the initial responders were struck," the sheriff said.

The first police officer who arrived chased and exchanged shots with Spengler, recounting it later over his police radio.

"I could see the muzzle blasts comin' at me. ... I fired four shots at him. I thought he went down," the officer said.

At another point, he said: "I don't know if I hit him or not. He's by a tree. ... He was movin' eastbound on the berm when I was firing shots." Pickering portrayed the officer as a hero who saved many lives.

The audio posted on the website RadioReference.com also has someone reporting "firefighters are down" and saying "got to be rifle or shotgun -- high-powered ... semi or fully auto."

About 100 people attended an impromptu memorial vigil Monday evening in Webster, a suburb of Rochester. Dozens of bouquets were left at the fire station, along with a handwritten sign that said, "Thanks for protecting us. RIP."

Investigators believe that Spengler set his family's home and a car on fire which spread to six other homes,officials said.

According to police officials, Spengler has a lengthy criminal record, including a manslaughter conviction for murdering his own grandmother, Rose Spengler, when he bludgeoned her to death with a hammer in 1980. Spengler Served 17 years in prison for the his crime.

Roger Vercruysse said William Spengler was a good friend when they lived next door in Webster, a Rochester suburb. He said Spengler "loved his mama to death." Arline Spengler died in October, and Vercruysse wonders what effect that had on her 62-year-old son. He says he thinks William Spengler "went crazy" after she died.

Over 30 residents were evacuated from the area, located on the shores of Lake Ontario, and kept aboard city buses for warmth.

New York Governor Andrew Cuomo released a statement saying, "New York's first responders are true heroes as they time and again selflessly rush toward danger in order to keep our families and communities safe."

“One behalf of my family and all New Yorkers, I offer my deepest condolences to the families and friends of those killed today and pray for the recovery of the injured.”

Webster, a middle-class, lakeside suburb, now is the scene of violence linked to house fires for two Decembers in a row.

Last Dec. 7, authorities say, a 15-year-old boy doused his home with gasoline and set it ablaze, killing his father and two brothers, 16 and 12. His mother and 13-year-old sister escaped with injuries. He is being prosecuted as an adult.

The Associated Press and FoxNews.com's Jana Winter and Perry Chiaramonte contributed reporting to this story.