SAN FRANCISCO , California ( CNN ) -- A wildfire threatened to decimate historic Angel Island , the largest in the San Francisco Bay , and a Marin County fire official warned it could take up to four days contain the blaze . At 9:15 p.m. Sunday the fire was burning only on the southeast side of the island . The fire , which began about 9 p.m. Sunday , had consumed about 250 acres of vegetation near the top of Mount Livermore 's 788-foot peak , Battalion Chief Mike Giannini said Monday . iReporter Bob Austrian , 45 , of Tiburon , said he could see the blaze from his home about 4 or 5 miles from the island . He noticed the blaze at 9:15 p.m. Sunday . It `` started as a little red glow '' on the southeast side of the island and worked its way over the top and around the side of Mount Livermore , he said early Monday morning . Watch the island burn » . `` It 's still ripping right now , '' Austrian said at 5 a.m. , noting that the blaze posed `` quite a spectacle '' with the town of Belvedere in the foreground and the Bay Bridge that connects Oakland and San Francisco serving as a backdrop . Fire crews and equipment were being ferried to the island to battle the blaze , Giannini said . About 200 firefighters were already involved in the effort or en route , he said . None of the blaze is contained , and Giannini said he expects the firefighting effort to last for three to four more days . Austrian , who has visited the island at least a dozen times , said he 's concerned that firefighters wo n't be able to douse the blaze . The island is mostly vegetation with a few historic buildings , foot trails and access roads . iReport.com : See , share images of the blaze . Even with the necessary manpower and firefighting resources , he said , it will be difficult to reach the actual blaze . `` It 's just the saddest thing because there 's no way to stop it , '' Austrian said . Fire officials said earlier that all of the park workers and campers on the island were safe . Angel Island -- a hilly grass- and forest-covered island -- is the largest in San Francisco Bay . The island was used as a quarantine station for immigrants suspected of carrying diseases starting in the late 19th century . It 's now a place for hiking , biking , camping and boating .
Blaze not contained , firefighting efforts could last four days , official says . iReporter : `` It 's just the saddest thing because there 's no way to stop it '' Blaze burning vegetation near the top of Mount Livermore 's 788-foot peak . All park workers , campers are safe , fire official says .