WEST COVINA (CBSLA)  — One teenager is dead and three others injured following a shooting at a house party in West Covina.

The shooting occurred around 10:30 p.m. Friday.

The shooter is still at large, police say.

CBS2/KCAL9 reporter Jeff Nguyen reported from outside the home where the shooting took place.

A grainy video of teens running for their lives was posted on social media. The video shows the teens running in front of Alvin Trivette’s home after a deadly shooting two-doors over.

“It was havoc. Kids just running up the block and screaming and horrified,” says neighbor Alvin Trivette.

The shooting left one young man dead and two male teens and a female with non-life threatening injuries.

Detectives say the house was advertised on social media and rented out for the party.

Trivette says his daughter got a copy of the flyer advertising the party at school.

Price to get in was $5.

But there was more:

“They were going to be selling NOS or Nitrous Oxide,” Trivette says, “There were so many kids walking to the party, each of them with two balloons in each hand.”

There is evidence they were selling NOS in balloons and the party goers were inhaling that to get intoxicated, a police spokesperson told Nguyen.

As you walk around the 300 block of North Hollow Avenue you can see balloon fragments scattered here and there.

A few in front of Van Sim’s house which is next door to the shooting.

“After shots rang out, they jumped over, to get away from the chaos. Jumped over my fence,” says Van Sims.

Nguyen found the address for the party house listed on the Air BnB website – which heavily booked up for June, July and about half of August.

Detectives believe the shooting happened in the backyard following an argument.

It’s believe about 30 to 60 people were the party but no one has come forward with information on the shooter.

Trivette says his sympathy is with the victim’s family.

“There’s some parents somewhere around here, they’re in a nightmare right now,” Trivette says.

Nguyen spoke to the family of the victim off camera. They were asking CBS2/KCAL9 not to reveal his name until all family could be notified. They did say the victim was 18 and about to graduate high school. They also said the victim’s 16-year-old brother was also one of the victims.

The family is asking anyone who might know the identity of the shooter to please call the LA County Sheriff’s Department.

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