Police in Minnetonka say a family is torn apart after a 16-year-old boy was stabbed to death by his 12-year-old brother. Officers called to an apartment Saturday night found the 16-year-old with a life-threatening stab wound to his chest. He was taken to North Memorial Medical Center where he later died. Investigators believe the 12-year-old used a kitchen knife to stab his brother while their mother and other family members were home. The juvenile suspect was taken to the hospital for an evaluation. Police are trying to determine what led to the stabbing.