CHICAGO — Two teenagers leaving their Loop high school were fatally wounded in a midday shooting Friday that startled onlookers under a busy “L” station in the center of the city. Around 12:25 p.m., the teens — 16- and 17-year-old boys — were leaving Innovations High School with about four other people, Chicago Police Department Deputy Chief Jon Hein said Friday. As the group was in the first block of North Wabash Avenue, two vehicles pulled up and several people exited before opening fire. Each boy was shot in the chest, and the older boy was also shot in the hip. The Cook County medical exam…