California's largest wildfire of the year was started by a sailor stuck on an isolated island who fired a flare gun to attract attention.
The 67-year-old was trapped on Santa Rosa Island in California's Channel Islands National Park.
The wildfire burned more than a quarter of the island, threatening rare Torrey pine trees found in only two locations in the United States.
According to the United States Coast Guard, the man became stranded after his sailboat struck rocks near Santa Rosa Island on Friday.
He remained on the island overnight before rescue crews reached him the following morning.
'The sailor fired emergency flares to signal for help, which inadvertently sparked a wildfire that grew to 1,000 acres by Friday afternoon,' officials from Coast Guard Air Station Ventura said.
Images from the scene showed the sailor had written 'SOS' in the scorched grassland.
More than 70 firefighters have been deployed to tackle the blaze, which has scorched nearly 14,600 acres since it began on Friday morning.
The fire, described by officials as human-caused, remained 0% contained on Monday.
California's largest wildfire of the year was started by a sailor stuck on an isolated island who fired a flare gun to attract attention. Pictured: The letters SOS carved out by the sailor on the island
The wildfire burned more than a quarter of the island, threatening rare Torrey pine trees found in only two locations in the United States
The National Park Service said firefighting efforts had been complicated by the outbreak of several mainland fires, including the Sandy Fire in Simi Valley, which has burned more than 1,300 acres, destroyed at least one home and forced thousands of residents to evacuate.
'Today new wildfires ignited on the mainland which immediately became the priority,' the Park Service said in an incident update.
'Per policy, firefighting resources are always assigned based on the greatest threats to life, safety, and property. This prioritisation helps ensure that the most urgent needs are addressed first during rapidly evolving fire activity.'
Efforts on Monday focused on protecting the island's Torrey pines, a rare species which exists naturally only on Santa Rosa Island and within a small reserve in San Diego.
However, officials confirmed the fire had reached the area where the trees grow.
'Unfortunately, the fire has reached the Torrey Pines area on the east side of the island,' the incident report stated. 'Upon initial assessments, fire crews are observing that the fire intensity was low and that the stand remains intact.
'When safe to do so, a fire effects crew will be assigned to make a full determination of condition and any long-term effect.'
Strong north-easterly winds, with gusts exceeding 30mph, hampered firefighting operations on Monday.
The National Park Service said firefighting efforts had been complicated by the outbreak of several mainland fires, including the Sandy Fire in Simi Valley (pictured)
Sandy Fire has burned more than 1,300 acres, destroyed at least one home and forced thousands of residents to evacuate
Pictured: A Fire Department helicopter drops water on the Sandy Fire as it burns in the hills near a residential area in Simi Valley, California on May 18, 2026
Despite the conditions, crews were able to create defensible space around buildings on the north-east side of the island and prepare roads for containment operations.
Firefighters were also working to protect the South Point lighthouse on the island's south-west side.
The Park Service said additional firefighters, all-terrain vehicles, hoses and pumps were expected to arrive on Tuesday, with specialised wildfire engines due to be transported to the island later in the week.
No injuries have been reported, but two historic structures on the island - Johnson's Lee Equipment Shed and Wreck Line Camp Cabin - have been destroyed.
Santa Rosa Island lies around 26 miles off the California coast and is home to several plant species found nowhere else in the world.