SAN DIEGO (FOX 5/KUSI) -- Officials have reopened the area around the Oceanside Pier after a fire broke out at the former Ruby’s Diner on the end of the pier Thursday afternoon. In an update Saturday, the City of Oceanside is reporting the water contact closure is lifted for the water around the Oceanside Pier after water quality testing was performed. Oceanside Pier fire rips through vacant restaurant The beach and Strand from Surfrider to Tyson Street has reopened, except for a 500-yard zone directly around the pier where officials are asking boaters, surfers and swimmers to continue to avoid that area. Oceanside Pier fire (FOX 5/KUSI)Oceanside Pier fire (FOX 5/KUSI)Aftermath of Oceanside Pier fire (FOX 5/KUSI) Aftermath of Oceanside Pier fire (FOX 5/KUSI) Aftermath of Oceanside Pier fire (FOX 5/KUSI) Aftermath of Oceanside Pier fire (FOX 5/KUSI) San Diego lifeguards fighting Oceanside Pier fire (Courtesy: San Diego Lifeguards) According to the City of Oceanside, two structures and the end of the pier were damaged when the fire broke out at 3 p.m. Thursday in the now vacant building that used to be Ruby’s Diner. Firefighters have been working since then to remove materials, identify hotspots and cool them with water to prevent re-ignition. After an hours-long battle to stop the flames from engulfing the entire end of the pier, Oceanside firefighters, with help from regional partners, were able to save 90% of the pier. San Diego lifeguards’ Triton fire boat assists in Oceanside Pier blaze The Oceanside Fire Department said firefighters have been working on the top side of the pier, supported by fire boats from the Oceanside Fire and Lifeguard Marine Safety Unit and the San Diego Harbor Police. Firefighters and a fire engine will be standing by Saturday night on fire watch, with overhaul work continuing Sunday. Officials say the cause of the fire has not yet been determined. The next update on the status of the pier is expected to come Monday afternoon. Christelle Koumoué contributed to this report