Police responded to reports of a shooting at a residence in the 5000 block of Wilmont Court shortly after 10:30 p.m.
The calls indicated that there were 70 to 80 people at the residence and many had run away.
Police arrived to find a sweet sixteen party thrown at the residence had ended in violence when an argument broke out between some of the 30 or 40 partygoers in the house's garage.
Numerous shots were fired from multiple guns, and a total of six were injured with graze wounds, a possibly broken leg and an abdomen wound.
Among the injured were a 13-year old Antioch resident, a 21-year-old Antioch resident, an 18 year-old Antioch resident, two 16-year old Antioch residents, and an 18-year-old Brentwood resident.
All six were transported to local hospitals, some by ambulance and others by helicopter. Some have been released from the hospital while others required more intense care and surgery.
Antioch police are investigating the incident, and received assistance at the crime scene from the Contra Costa County Sheriff's office, Pittsburg police and Brentwood police.