An Oktoberfest celebration in Huntington Beach, California, descended into chaos Saturday after several explosions injured five attendees. According to local authorities, the explosion erupted from an underground electrical vault around 8:00 p.m., sending flames flying over the Old World Village shopping and dining complex, roughly 35 miles south of Los Angeles.

Local fire department Battalion Chief Jeff Lopez confirmed that two firefighters and two restaurant workers received treatment for minor injuries, while another restaurant employee suffered moderate to severe injuries and required more extensive treatment.

Attendees began to flee the scene immediately as police began evacuation procedures. A HAZMAT team arrived soon after the area was cleared to assess the situation.

As many as 1,700 locals lost electricity due to the blast. Crews worked through the night to replace the exploded transformers and restore power.

Early reports say the cause of the explosions is still under investigation. The first explosion splattered mineral oil which is believed to have caused subsequent blasts. The oil is typically used to cool the vault's transformers.

Witnesses reported hearing up to three explosions at the festival. One guest told reporters that she saw flames shoot up as high as 40 feet.

“It was just like one giant fireball that went up,” the guest told the Long Beach Press-Telegram. “And then there was a second explosion maybe 10 or 20 seconds later.”

Men in traditional Bavarian dress celebrated Oktoberfest 2014. Getty Images