Four firefighters were shot — two fatally — after responding to an early morning blaze on Monday in Webster, N.Y., about 12 miles northeast of Rochester, officials said.
The Webster police chief, Gerald L. Pickering, said at a news conference that the firefighters were "fired upon by one or more shooters."
The scene of the fire, which continued to burn through the morning as it spread to several houses, remained "an active crime scene," Chief Pickering said, though officials said there was no further shooting.
Strong Memorial Hospital in Rochester said two firefighters were in "guarded condition."
Evan Dawson, a reporter for WHAM-TV in Rochester, said on Twitter that relatives of one firefighter said he had been shot in the back and seriously injured but was expected to survive.
The firefighters were from the West Webster Fire Department, about four miles from the blaze.
Chief Pickering said that, with authorities establishing and investigating the crime scene, "it took a while to make it safe" for firefighters to move in and combat the flames.
The site of the fire, Lake Road, runs along a narrow spit of land that divides Lake Ontario from Irondequoit Bay. Houses near the affected area are detached wood-frame homes with yards, across the street from the lake.
Michael D'Amico, a contractor who has lived on Lake Road for 20 years, said residents were evacuated to a school. "We still can't go back," he said.
He said four houses had burned so far. The area is home to many summer houses, he said, but some people lived there year-round.
"A lot of times I get woken up by gunfire, but I don't think too much of it," Mr. D'Amico said, noting that the area often attracted duck hunters.
"Usually the gunfire comes from the lake or the bay," he added. "This was from further down the road."
J. David Goodman contributed reporting.