A firefighter was injured Wednesday while helping to put out a house fire in the 913 Seneca Street in Fountain Hill. At about 5 p.m. yesterday, a resident of the two-unit apartment house came home from pushing her baby in a stroller and found the building on fire and firefighters were already there, according to The Morning Call. A firefighter hurt his knee when he fell inside the house. Fountain Hill Assistant Chief Dan Pope said the firefighter was taken to St. Luke’s University Hospital for treatment, The Express-Times reports. The fire displaced three adults and an infant from the second …