It was a football party that ended in fear and fatalities.
At least 10 people shot in the California city of Fresno on Sunday night.
Three men died at the scene.
Another succumbed to his injuries in hospital, where five others are in a critical condition.
Police said all those killed were between the ages of 25 and 25.
(SOUNDBITE) (English) DEPUTY CHIEF OF FRESNO POLICE DEPARTMENT, MICHAEL REID, SAYING: "There was about 35 people that were inside the house and inside the backyard.
They were at a football party, so this was a family gathering.
The initial information is that somebody came up on foot possibly, at least one suspect, and began firing.
They fired into the backyard where most of the people were in this party.
Striking ten people." Who did it, why and where they are is a mystery at this stage.
Police have been combing the area for witnesses and CCTV footage as the search for answers begins.