O'Flynn lamented the violence, which comes on the heels of other shootings including the massacre of 20 students and six adults at Sandy Hook Elementary School in Newtown, Conn.
"It's sad to see that that this is becoming more commonplace in communities across the nation," O'Flynn said.
Gov. Andrew Cuomo said the State Police and Office of Emergency Management were working with local authorities.
"Volunteer firefighters and police officers were injured and two were taken from us as they once again answered the call of duty," Cuomo said in a statement. "We as the community of New York mourn their loss as now two more families must spend the holidays without their loved ones."
Webster, a middle-class 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.