It happened around 10:00 a.m. in the 1700 block of West 4th Street.
Firefighters arrived to find heavy smoke and flames coming out of an apartment over a grocery store.
The residents were able to get out on their own, though a female suffered a burn to her forearm and was taken to St. Francis Hospital.
A firefighter suffered a leg injury battling the blaze.
The American Red Cross of the Delmarva Peninsula assisted three families (15 individuals) after the fire. The Red Cross is providing each family with groceries, clothing, temporary shelter, comfort kits, and stuffed animals for the children.
