Emma Jacobs attends a 9/11 memorial event at Fireman’s Hall. Tom MacDonald looks at the different plans the mayor and City Council have for the Philadelphia schools. Elana Gordon visits area schools grappling with preventing and treating head injuries from contact sports. In this week’s “The Short Answer,” Maiken Scott and Zack Seward answer questions about the Affordable Care Act. Mary Cummings Jordan meets David Livewell, whose poetry preserves the memories of old Philadelphia working class neighborhoods.