A man drinking beer in one hand and brandishing a gun in the other opened fire on Sunday at a birthday pool party at an apartment complex in California’s San Diego in the United States, local media said.

Seven people were shot in the incident. One woman who was shot died, several victims were in surgery and others were still critical late Sunday, Chief Shelley Zimmerman said at a news conference. An additional man was taken to the hospital after he broke his arm while fleeing.

Police soon intervened, shooting and killing the 49-year-old man identified as Peter Selis.

A police helicopter arrived to the scene first and the pilot reported seeing multiple victims on the ground and that the suspect, Selis, was still in the pool area and appeared to be reloading.

Three officers on the ground shot the suspect after he pointed a large-caliber hand gun at them, Zimmerman said.

Police believe that Selis lived in the complex but have not discovered a motive. They are investigating.

Rikky Galiendes, 27, heard gunshots around 6 p.m.and went to look outside his sixth-story apartment when he spotted a man bleeding and running near the pool below. Galiendes told The Associated Press that he called out to ask if the man needed help when his roommate grabbed him, yanked him down and then pointed toward a man sitting in a chair with a gun.

“When we looked over the balcony, he was just sitting down with a gun on his lap,” Galiendes said. “He was calm, you know. I mean from my perspective, the guy was ready to do whatever he was going to do. He shot at people having a good time and having a party.”

Galiendes and his roommate ran back inside and called police. They stayed indoors until neighbors yelled that it was safe to come out. Galiendes said it was a horrifying scene.

“As soon as I heard the gunshots I had goosebumps and the whole thing was really emotionally draining — seeing blood everywhere, seeing bodies on the ground, hoping they survived, seeing bloody footsteps you know of people who ran away. There was just so much blood. It was so surreal.”

Galiendes, a full-time communications student at the University of California San Diego, said he has lived in the complex since September.