North Port police today ruling that a deadly fire that killed a mother and son is a case of arson. The early-morning blaze in the 2500 block of Duar Terrace yesterday claimed the lives of 43-year-old Carol Wisdom and her eight-year-old son, Michael. Arson investigators today saying the fire was caused by what they’re calling “an unknown accelerant” in the garage area of the home. That makes it arson and as of today, the blaze in being investigated as a double-homicide.