Despite being legally mandate to take care of learners under in loco parentis principle, public boarding secondary schools in Kenya continue to suffer catastrophic fire outbreaks. The study examined the structural, operational and psychosocial factors influencing fire disaster preparedness in the county of Machakos, which was also hit by the 2001 Kyanguli fire accident in which 67 students lost their lives. This study adopted cross sectional mixed methods approach based on Maslow's hierarchy of needs theory and Erikson's psychosocial development theory. The questionnaire was returned by 73 principals (62.3% response rate), 207 teachers (60.5% response rate), and 268 students (69.1% overall response rate), in addition to physical audits at all 117 schools. Descriptive statistics and chi-square tests were used to analyse the data. The findings showed that there were significant gaps between policies and practices. 64.2% of students reported having no knowledge of a fire evacuation plan, while 47.9% of principals said they had a completely functional fire evacuation plan. 41.1% of schools had never had a fire drill and 90.3% of the students were not able to use a fire extinguisher. Of the schools, 65.8% of smoke detectors were rated very inadequate, and 43.8% of dormitories had external locks on the night. The most predominant conflict-resolution method was punitive discipline (89.6% of students) and 60.1% of students experienced no professional counselling. The evidence suggests that fire vulnerability continues to be maintained through the lack of operational safety programmes, gaps in safety equipment, non-compliant architecture and a lack of attention given to the psychosocial needs of adolescents. In addition to greater regulatory enforcement, the following activities are in urgent need of being introduced at that cost: door re-fitting, de-grilling, mandatory drills and/or professional counselling services.