Crown Heights residents volunteered through a blood drive today to help a firefighter recover from severe injuries suffered in the line of duty. Firefighter Robert Wiedmann was badly scarred last month battling a house fire on Prospect Place. He is currently recovering at Weill-Cornel Medical Center's burn unit. Blood drive organizers say nearly 100 people attended the event, and that donors came whether they knew Wiedmann or not. The firefighters union says Wiedmann is alert and speaking, and that he has started walking again.Special blood drive being held for injured firefighter