A nonprofit group announced Tuesday that it has paid off the mortgage of an Inwood firefighter killed in the line of duty.

Assistant Chief Joseph Sanford Jr. died two days before Christmas last year from injuries he suffered while fighting a house fire. During the incident, the 17-year veteran fell through the first floor of the under-construction home and was found in the basement unconscious. He died at the hospital several days later.

The Stephen Siller Tunnel To Towers Foundation and Bank of America have now agreed to help pay off the family's mortgage.

Sanford is survived by his wife and daughter.

Tunnel to Towers honors the sacrifice of fallen firefighter Stephen Siller, who ran through the Brooklyn Battery Tunnel on Sept. 11, 2001 while wearing his gear to save lives at the World Trade Center.

The foundation previously paid off the mortgages of slain NYPD detectives Wenjian Liu and Rafael Ramos.