Earlier this month, more than 60 iron workers gathered on Shattuck Street to meet and cheer on 7-year-old Ava, who is undergoing radiation therapy at BWH and is also a patient at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. The iron workers—who call themselves Ava’s Army—surprised Ava with her own banner on Shattuck Street, facing the windows of a Boston Children’s Hospital building.