The fire burned grass and brush in the lagoon producing smoke that was visible from Interstate 5.
A fire in a North County lagoon created flames rising 30 feet into the air and briefly threatened a nearby apartment complex.
The fire started in a homeless encampment along South Coast Highway between Carlsbad and Oceanside just before 5:30 a.m.
Flames reached as high as 30 feet officials said. While no structure burned in the fire, the flames came within 30 feet of row of townhomes on nearby Eaton Street. Residents were not evacuated.
Firefighters initially said four acres burned in Buena Vista Lagoon but later revised the damaged area to two acres.
New clumps of reeds and brush were burning as of 7:30 a.m. but fire crews described it as a slow rate of spread.
Oceanside and Carlsbad Fire Departments called in a fire helicopter because the lagoon was too marshy for ground crews to access.
Several nearby residents alerted by the sound of crackling coming from the lagoon, walked over to see the smoke rising across the water.
Trains were running on schedule.
Drivers were redirected at Carlsbad Boulevard and Beach Avenue.
Check back for updates on this developing story.