Firefighters responded to a fire at San Francisco's Pier 29 on Wednesday afternoon.
Firefighters were called to the building on the Embarcadero, whose roof or top floor appeared to be on fire around 1:50 p.m.
The fire reportedly broke out at a construction site, which is also scheduled to be the home of the America's Cup.
The Embarcadero was closed from Bay Street to Broadway. The fire was contained just before 4 p.m.
The cause of the fire was not immediately known. Huge flames and thick black smoke were seen rising above the building.
"It has gone to a fourth alarm, which is approximately 100 plus personnel," San Francisco Fire Department Captain Jeanne Seyler said. "It is a building vacant of businesses."
The facade of the pier was built in 1915 and it was made out of concrete. Officials said the facade began to fall because when it heats up, the concrete dries out, causing it to crack and separate.
While the building was not housing any businesses, it did have some cars stored inside.
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A small portion of the roof of Pier 29 fell onto the sidewalk but no one was injured.
Traffic in the area was being diverted and flames could be seen from the historic Ferry Building. Firefighters were on the roof of Pier 29 battling the blaze by hand.
There were no initial reports of injuries.
The building is located in a highly trafficked area between the Ferry Building and Pier 39 right along San Francisco's bay front. between Broadway and Chestnut Street.
A Muni official said the F line was switched back in- and outbound at the Ferry Building due to the fire.
Alternative routes included Muni lines the 30 Stockton, the 8X, the Powell-Hyde and Powell-Mason cable cars.
The Pier 29 site was considered a vital negotiation piece to bring the America's Cup to San Francisco in 2013.
Organizers of the sailing race were said to be prepared to spend upwards of $55 million to restore piers along San Francisco's waterfront.
Below are images and thoughts from Twitter: [View the story "Pier 29 Burns" on Storify]
