The first Webster police officer who arrived on the scene exchanged gunfire with the shooter, Monroe County Sheriff Patrick O'Flynn said.
Police would not give details on the whereabouts of a suspect, with O'Flynn saying only there was no active shooter at the scene later Monday morning.
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 started to take on rounds and the initial responders were struck," the sheriff said.
The fire started in one home and spread to two others and a car, officials said.
The two wounded firefighters were in critical condition at a Rochester hospital, Flynn said.
The Rochester Democrat and Chronicle reports that police are evacuating residents of the peninsula.
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