Authorities said the Balugo River and tributaries overflowed their banks and flooded much of the villages in the cities of Silay, Talisay and Victorias.
Marjorie Salva and her 10-year-old daughter Rhoda were crushed to death when rising waters pushed the wall of a lumber yard onto them near Silay, the provincial administration center said.
Rescuers, meanwhile, found 60-year-old Mercedita Dador dead. She apparently suffered a stroke at the height of the floods.
Emilia Villavicencio, head of the social welfare department in Silay, said about 90 percent of the city center was underwater yesterday morning.
Silay police chief Ricardo de la Paz advised commuters from northern Negros to delay their trips because national roads remained impassable.  Antonieta Lopez