Just before 9:30 p.m., emergency crews responded to reports of a man down in the 700 block of Fourth Street, police said. The crew found Maggio unresponsive and located a stab wound on the left side of his chest as they began to treat him.
Maggio was taken to a local hospital where he died, police reported.
An autopsy will determine whether Maggio suffered injuries other than the stab wound.
Officers searched the area but did not immediately identify a suspect.
The case is being investigated as a homicide and anyone with information is asked to call the Violent Crimes Unit of the Santa Rose Police Department at (707) 543-3590.