A man who was inside the California bar where a mass shooter killed 12 people Wednesday night gave a heart-wrenching apology to the wounded and the dead — for getting himself and his stepson out safely and not attempting to stop the gunman.

“I should’ve stayed ’til he changed his clip, but I was worried about my boy,” said the tearful man, identified only as Tim. “I apologize to anybody who got hurt or passed.”

Tim was getting ready to leave the Borderline Bar & Grill in Thousand Oaks with his stepson after playing pool Wednesday night when smoke started pouring into the bar, and he heard a gunshot.

“I knew it was live. I knew it was real,” Tim told the local ABC affiliate. “My son thought it was a joke, so I pulled him down and got some cover.”

The shooter continued his rampage, hitting the front doorman and the cashier, who was “just a young girl,” Tim said.

“He didn’t say anything, he just started shooting,” Tim said.

Tim’s stepson, John Hedge, told the outlet he heard at least 12 shots by the time he was able to escape.

Before the rampage, the gunman, who had a beard and wore a hat and black jacket, was throwing smoke bombs in the front of the bar, Hedge said.

“I was at the front door and I was talking to my stepdad,” he said. “I just started hearing these big pops. Pop, pop, pop.”

When the gunman pointed to the back of the cash register and kept firing, Hedge made his escape, he said.

Officials say 12 people, including a sheriff’s sergeant, are dead and 10 others were injured. The gunman also was killed.