Matt Wennerstrom said he immediately recognized the sound of gunfire. He smashed a window with a barstool to rescue people in the bar as the shooting was taking place.
"We probably pushed 30 or 35 people through that window," Wennerstrom said.
Blood was visible on the sleeve of his shirt.
"All I did was grab as many people as I could and pull them underneath the table until I heard a break in the shots, and then we got people out of there, as much as we could," he said.
One woman who went through the window was in tears describing the event.
Wennerstrom, who said he visits Borderline Bar & Grill every week, said all he wanted to do was get his friends to safety.
The shooting happened around 11:20 p.m. Wednesday at Borderline Bar & Grill. Authorities said hundreds of people were inside the bar when the gunfire rang out.
The shooting left 12 people dead, including a Ventura County sheriff's sergeant, authorities said.
Authorities said the suspect was killed inside the venue.