holvis tonight on kron4 news at 8:00 p.m.. >> getting a look at your commute home, it is looking a littlebe a slow ride home. family has been following a developing story all day one firefighter has died in other is fighting for his life. it it is a fire in the diamond heights area and the firefighter that died, 48 year-old vincent perez died of cardiac arrest. they say big flash over an explosion occurred while fighting the fire. the other firefighter that is in critical condition, anthony valerio is behind me in the hospital at this hour. the grandmother and the three grandchildren that were in the house managed to escape without injury. a third firefighter battling the blaze suffered minor injuries, she has been released, one firefighter said, i never in critical condition at this hour. we are live at san francisco general. >> continuing our coverage i am just down the street where the fire broke out. you can see the arson task force investigators on scene, i spoke with a neighbor of earlier today that describe what it was like as the firefighters should carry out their fallen comrades