Grabs from video show numerous emergency responders at the scene assisting with victims and loading patients into ambulances.  The video also shows at least two Injured attendees limping and needing assistance due to injuries.  A woman could also be seen sitting in the street crying.  The Contra Costa Sheriff's Office tweeted, Orinda Police Department and Contra Costa County Office of the Sheriff are working a multiple shooting in Orinda. Investigation is active." Police were investigating a Halloween night shooting involving multiple victims, authorities told CNN affiliate KPIX.
4 killed in California Halloween party shooting
00:31 - Source: HLN
CNN  — 

A fifth person wounded in a shooting at a Halloween party in Northern California has died and the shooter remains on the run, authorities said.

Gunshots rang out Thursday night at the crowded party in Orinda, which was advertised on social media. When officers arrived, they found a house party with more than 100 people, the Contra Costa County Sheriff’s Office said in a statement.

“Arriving officers found a highly chaotic scene that included gunshot victims, injured party-goers, and numerous people fleeing the scene. The partygoers apparently came from throughout the Bay Area for the Halloween event. … The party took place in a home that was found on a short-term rental website,” it said.

Two firearms were found in the house and a crime lab is analyzing them to determine whether they were used in the shooting or any other crimes, authorities said.

The victims killed were Oshiana Tompkins, 19; Tiyon Farley, 22; Omar Taylor, 24; Ramon Hill Jr., 23; Javin County, 29. Three were pronounced dead at the house, and two others died at the hospital, according to the sheriff’s office.

It was unclear how many victims were injured since some were taken to the hospital by ambulance while others drove themselves, the sheriff’s office said.

The shooting happened at an Airbnb rental that prohibited parties. Airbnb said it was horrified by the tragedy and it’s cooperating in the investigation.

Before the shooting, Orinda police officers were called to the house at 9:19 p.m. and about an hour later regarding a noise complaint.

“At 10:48 p.m., an officer was headed to the home to investigate the calls,” the sheriff’s office said. “The initial reports of shooting came in around 10:50 p.m.”

Orinda is a suburb east of Berkeley in the Bay Area.