A Tyler man has died after suffering a heart attack when he tried to help his mother-in-law stave off an attack by her neighbor's pit bulls. Van Zandt County Sheriff Pat Burnett said the mother-in-law tried to intervene when the pit bulls attacked her two dogs Thursday, but was knocked down and bitten by one of the pit bulls. The sheriff said the pit bull that bit the woman was stabbed and killed with a pocket knife by her son-in-law, who later had a heart attack while the woman was being treated. Burnett told the Tyler Morning-Telegraph that paramedics couldn't...