Authorities said they got a call of shots fired on the 1100 block of North Willow Avenue around 8 p.m.
According to investigators, two men approached partygoers and got into an argument with them. Several shots were fired. Police said it appears that both suspects were armed.
One man was pronounced dead at the scene. A 24-year-old man was struck in the leg and a 28-year-old man was struck in the hand and abdomen. Both were rushed to the hospital.
The suspects fled on foot. Anyone with information was asked to call Rialto police at (909) 820-2550.