A Huntington Beach restaurant owner who asked patrons to leave the area near the site of a transformer before it exploded and rattled a crowded Oktoberfest celebration on Saturday night was “badly burned” and “fighting for his life,” his family said the next day.

A post on the Facebook page for Old World Village’s German Restaurant identified the owner as Bernie Bischof. The blast happened around 8 p.m. as Bischof led two firefighters to the eatery’s patio area, where he had detected a smell from an underground vault that held three transformers, the Los Angeles Times reported. The impact knocked them down, said Battalion Chief Jeff Lopez with the Huntington Beach Fire Department. The two firefighters lost sight of the person who guided them there and were looking for him when another explosion followed, according to the Fire Department. The firefighters were taken to a burn center and later released. Bischof, meanwhile, sustained second- and third-degree burns on nearly 40% of his body and remained in critical condition on Sunday, a restaurant spokesman told the L.A. Times. The business had been filled with 1,000 people the night of the incident, the spokesman said. Jim Osuna, who identified himself as Bischof’s friend, said the restaurant owner has been raising two young sons on his own after his wife passed away. “They’re still struggling with their mom passing, and now with this happening to Bernie it’s tough for the family,” Osuna told KTLA. A total of five people were hurt, according to the Fire Department. Three of them were civilians and all but one have been released from the hospital, the agency said. “Bernie is a hero and is fighting for his life,” his sister, Cyndie Kasko, said in a Facebook post. Former and current employees helped Sunday as Southern California Edison cleaned up “this big mess,” she added.

The utility company has not said what caused the transformer to explode. Crews managed to quickly extinguish the fire that ignited, authorities said. The family says Bischof called Edison about a week before the explosion regarding strange noises coming from the vault. Edison told KTLA it is looking into that claim. The incident knocked out electricity for at least 300 customers overnight, according to officials. The restaurant planned to be back in business Monday and resume Oktoberfest Huntington Beach on Wednesday to “celebrate the survivors of this tragic event,” Kasko said on Facebook. Her father, Josef Bischof, came to the U.S. in 1952 and “dreamed of bringing with him a piece of his homeland to share with his new friends in a new land,” according to Old World’s website. With his wife, he would build 45 Bavarian-style restaurants. The Huntington Beach business has been celebrating Oktoberfest since the 1970s, the website said. Osuna said the long-running restaurant’s clientele is its own sort of family. “It really is, as you can see by the outpouring tonight,” he said. “A lot of people care for Bernie, and he is a good guy. And he was a hero that day. If he hadn’t acted as quickly as he had, I think things could’ve been a lot different.” Osuna added that Bischof is “a strong guy, and he’ll bounce back.”