California State University, San Marcos sits in the hills just north of where the Cocos Fire ignited. On May 14, students were in the midst of spring finals when evacuation orders came. The university closed for the rest of the week, and commencement exercises scheduled for the weekend were cancelled entirely. Palomar College also shut down on May 15 and 16, postponing its graduation ceremonies until the following week. For thousands of students, years of academic work culminated not in celebration but in evacuation, their final exams and graduation ceremonies displaced by walls of smoke visible from Highway 78.

The fire spread rapidly through San Marcos and into Escondido, fueled by the dry conditions that define San Diego County in May. By the afternoon of May 15, the blaze had grown significantly. Firefighters worked to contain the perimeter while more than 40 buildings burned, including those at Harmony Grove. Property damage exceeded $5.7 million, though only three minor injuries were reported. The Cocos Fire earned the distinction of being the last of the May 2014 wildfires in the county to be fully contained, with Cal Fire announcing 100 percent containment at 6:30 PM on May 22, eight days after ignition.

On July 9, 2014, the San Diego County Sheriff's Department announced they believed the Cocos Fire was intentionally set by a 13-year-old juvenile. The trial held in March 2015 revealed that the teenager had lit a fire in her Washingtonia Avenue backyard in San Marcos. A blown ember from that fire, known as the Washingtonia Fire, sparked the Cocos Fire. On March 24, 2015, the then 14-year-old was found guilty of multiple counts of arson and one misdemeanor count of unlawfully allowing a fire to escape her control. The judge concluded she had acted 'intentionally and maliciously.'

On May 27, 2015, the teenager learned her sentence: 400 hours of community service, letters of apology to every victim, and at least $40,000 in restitution. She was also ordered to enroll in Breaking Cycles 365, a rehabilitation program designed to prevent juveniles from becoming repeat offenders. For the residents of Harmony Grove who lost everything, for the families whose homes burned, and for the students whose graduations were cancelled, the sentence attempted to balance accountability with the reality of juvenile justice. The spiritualist community has worked to rebuild what 118 years had created and one afternoon destroyed.