Four volunteer firefighters were shot -- two fatally -- as they responded to a blaze early Monday at a small cluster of homes along Lake Ontario in Webster, N.Y.
The firefighters were shot as they exited their vehicles after being called to the scene just before 6 a.m. ET, police and fire officials said.
It appears they were the victims of a "trap," police said.
"People who get up in the middle of the night to fight fires, they don't expected to get shot and killed," said Webster Police Chief Gerald Pickering, his voice breaking at times.
One firefighter was able to flee from the shooter under his own power. The others were pinned down on a narrow strip of land between Lake Ontario and Irondequoit Bay until a SWAT team arrived.
The apparent shooter was pursued by police and is dead from a gunshot wound, Pickering said. It is unclear if the wound was self-inflicted.
The two injured firefighters are being treated for "significant injuries," according to Dr. Nicole Stassen, a surgeon at the University of Rochester Medical Center. But she said they are both awake and alert, and not on ventilators.
An off-duty police officer in the area also received a shrapnel wound. His condition is unclear at this time.
After the shooting, the fire grew to engulf at four homes and one motor vehicle. Another four homes were damaged.
"These firemen are part of our family. You go into a fire with these guys. To see them go down with something like this is totally unexpected. We are in shock," Billy Gross, fire commissioner for West Webster, told the Rochester Democrat and Chronicle.
After the shooting, dozens of area residents were evacuated, with police searching them as they left, the newspaper reported.
"Miserable thing to happen this time of year," Mark Johns, a state assemblyman who represents the area, told local NBC station WHEC. Johns said he knew some of the firefighters who were shot.
Michael Damico was among those forced to flee, according to the Democrat and Chronicle.
"The whole strip's been evacuated," Damico said. "They're evacuating all of the houses and going through them."
New York Gov. Andrew Cuomo issued a statement after the shooting, offering his "deepest condolences."
"All of our thoughts and prayers go to the families and friends of those who were killed in this senseless act of violence," Cuomo said. "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.
NBC's Tom Winter and Rosanna Arlia contributed to this report.
Jason White, NBC News