An FDNY firefighter was knocked unconscious when an air conditioner fell from a window and struck him in the head while he was battling a Brooklyn blaze on Monday morning.<br /><br />The shocking incident took place outside a home in Bensonhurst and sent the smoke eater from Ladder 172 to the hospital where he was in serious condition, according to FDNY sources.<br /><br />The firefighter was among 106 members of the FDNY who fought the two-alarm blaze that broke out just before 9 am at a house on 85th Street near 20th Avenue.<br /><br />Fellow bravest could be seen rushing to the man’s aid, with one screaming, “medic!,” according to the footage.<br /><br />The firefighter was taken to Lutheran Hospital for treatment.<br /><br />The FDNY said five other firefighters suffered minor injuries while extinguishing the two-alarm blaze.