San Francisco's ex-fire commissioner has said the city is 'burning' after the District Attorney dropped charges against a vagrant who repeatedly bashed him in the head with a metal crowbar. Don Carmignani, 53, was left fighting for his life after being brutally attacked on April 12, when he sprayed pepper spray at the homeless man outside his mother's home in the Marina District. He suffered a fractured skull and jaw in the attack, and required 51 stitches after Garrett Doty, 24, allegedly beat him over the head with a crowbar. Carmignani - who served as a fire commissioner in 2013...