An anonymous tip led to the discovery that 10 college students, aged between 18 and 22, had gathered for a late night hangout at an abandoned property where the fire originated, Santa Barbara County Sheriff Bill Brown said. He declined to say which college the students attended.
"It appears this fire was the result of carelessness, not criminal intent," Brown said.
No criminal charges have been filed, but the county district attorney will review the case, Brown said.
The fire consumed nearly 2,000 acres in Santa Barbara County and critically injured a couple who were burned as they fled their home, which was destroyed by the flames.
The college group left the smoldering bonfire in the middle of the night and the embers sparked the wildfire 13 to 14 hours later, Brown said. The group had been hanging out at a property known locally as the "tea garden" next to an abandoned tea house in the hills of Montecito.