Two firefighters who survived an ambush in upstate New York that killed two of their colleagues said Thursday they were "humbled and a bit overwhelmed" by well wishes in the wake of the tragedy as more details emerged of the deadly attack.

West Webster volunteer firefighters Joseph Hofstetter and Theodore Scardino, who had been in guarded condition, were upgraded to satisfactory condition on Wednesday at Rochester's Strong Memorial Hospital.

As authorities continued their investigation into the assault that William Spengler, 62, carried out on the volunteers responding to a blaze in Webster early Monday, the hospital released a statement from the survivors.

The pair said their "thoughts and prayers" were with the families of their colleagues Michael Chiapperini, 43, and Tomasz Kaczowka, 19, who were shot dead at the scene. They were also "humbled and a bit overwhelmed by the outpouring of well wishes for us and our families," the statement said. 

Chiapperini was killed by a single gunshot wound, while Kaczowka died as a result of two gunshot injuries, according to autopsy results released by New York State Police on Thursday afternoon.

Spengler, who was convicted of killing his grandmother in 1980, died of a self-inflicted gunshot to the head, police said in a statement. He shot himself as seven houses burned around him.

'Multiple firemen down'
"We are being shot at," an unidentified voice told a 911 dispatcher in a recording aired Wednesday on NBC's TODAY. "Multiple firemen down. Multiple firemen are shot. I am shot. I think he is using an assault rifle."

Hofstetter and Scardino were shot during the chaos. One was struck by a bullet in the pelvis and the other in the chest and knee, NBCNewYork.com reported. 

Police said Spengler left a three-page typewritten note saying he wanted to burn down the neighborhood and "do what I like doing best, killing people."

“He was equipped to go to war, kill innocent people," Webster Police Chief Gerald Pickering told reporters Tuesday.

The Rochester Democrat and Chronicle said Wednesday that the funeral for Chiapperini, who was a 20-year veteran of the Webster Police Department, will be Sunday, while a funeral Mass for Kaczowka, who graduated from high school last year, will be held in Rochester at 10 a.m. ET Monday.

John Ritter, a police officer with the nearby Greece, N.Y., police department, came across the fire while on his way to work early Monday. He stopped, waiting to see if the firefighters would direct him around the scene, when he suddenly heard a large blast and then discovered a hole in his windshield, The Rochester newspaper reported. His vehicle was struck a second time.

“At that point I didn’t know what it was. I didn’t know if it was shrapnel from the fire. I sat there, I checked my body to see if I was injured -- I wasn’t -- and then I heard multiple rounds going off,” he said late Wednesday at a press conference.

He made his way over to where firefighters were trying to put out the blaze and warned them that someone was shooting. He told the newspaper his main goals were to take cover, get out of the “kill zone” and keep people from that area. Though he called his role “peripheral,” police have said he helped to protect others.

“There’s no way to defend an ambush,” said the nearly 24-year veteran of the Greece police force, who did not open fire. “I am driving to work ... I don’t have any tools of my trade with me. I don’t have body armor, I don’t have long range weapons, I don’t have my radio, I don’t have anything, and I am in a situation where someone is actively engaging me.”

Ritter said words couldn’t describe his feelings, which included survivor’s guilt. “I don’t know why I’m still here, other than there was some type of divine intervention that kept that round from penetrating through my car and hitting something else.”

Spengler had lived in the house with his sister and his mother, Arline, who died in October at 91. Arline Spengler's obituary asked that memorial donations be made to the West Webster Fireman's Association.

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A former neighbor told The Associated Press that Spengler "loved his mama to death" and that he "couldn't stand" his sister. The neighbor said he thought Spengler "went crazy" after his mother died.

Spengler, the gunman, was convicted of manslaughter in 1981 after the death of his grandmother, Rose Spengler, 92, and was paroled in 1998. He remained under parole supervision until 2006, the Democrat and Chronicle reported. Before Monday's shooting, Webster police hadn't had any run-ins with Spengler since he was paroled, they said.

Police investigating the killings said Tuesday that they had found what appeared to be human remains at the gunman's home. Authorities said they believed those were of Spengler’s 67-year-old sister, Cheryl, who lived with him.

Although Spengler couldn't legally own firearms as a convicted felon, police said he was armed with a Smith & Wesson .38-caliber revolver, a 12-gauge pump shotgun and a Bushmaster .223-caliber rifle, the same kind used in the Newtown, Conn., school massacre in mid-December. Authorities are tracing the history of the weapons and how Spengler obtained them, state police said.

At least 33 people were displaced by the fire, which engulfed at least seven homes and a motor vehicle.

The Associated Press contributed to this report.

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