At 90 years old, a Staten Island man has lived through a lot in his life. But he probably never expected to be fighting for his own -- after being mauled by pit bulls. The man is in such bad shape, he doesn't know the owner was just arrested. On Tuesday night, the dogs' owner was being held at the 120th Precinct stationhouse charged with not having his pit bulls on a leash or collared with tags. Popeye and Brutus are the two pit bulls who witnesses say mauled 90-year-old Henry Piotrowski so badly the elderly victim had to have one leg amputated at the knee and is at risk of losing an arm. "The man looked up at me and asked me to help," witness Stephanie Morton said through tears. Piotrowski was outside his Port Richmond home when neighbor Reginald Bell said he heard Piotrowski's cries for help and saw the two dogs attacking him. Bell grabbed a butcher knife to chase the dogs away. "I've seen some horrific things in my life but that was far beyond anything I could have ever...