Crews aboard firefighting boats extinguished a fire that burned Friday morning at the former Ruby's Diner building on the end of the Seal Beach Pier.
A strong ocean breeze fanned the fire as powerful water cannons were used to attack the flames, which were shooting through upper level windows before the roof collapsed. The fire began at about 8 a.m. on the 2,000-foot long pier, which is the second-longest wooden in California, according to the city.
Firefighting boats surrounded the tip of the pier because the wooden structure, built in the 1900s, could not hold the weight of a fire truck, according to firefighters.
A firefighter suffered a shoulder injury.
Details regarding a cause were not immediately available.
"It sort of puzzles me because there's nothing out there to catch fire," said resident "Lucky" John Domingue. "There are buildings, but the electrical should have turned off. It's been empty for three years, so who knows."
Parking lots were closed on both sides of the pier, and firefighters asked that visitors stay out of the water as the investigation continued into Friday afternoon. Smoke still wafted over the area hours after the fire.
Ruby's Diner closed in 2013 after more than two decades on the pier, which was rebuilt in the 1980s after a storm destroyed two sections.
"It all happened so quickly," said witness Madi McCulloch. "It just went up in flames. It was kind of sad."
For those who live here it's a sentimental setback.
"Maybe it's the nostalgia of walking on wood, feeling the ocean breeze, enjoying life," said Tony McCormick, a Seal Beach resident.
NBC4's Nyree Arabian contributed to this report.