Due to a grandfather clause that did not require schools to retrofit to a new standard if they already met previous regulations, the school legally complied with the State of Illinois and City of Chicago fire codes of 1958 and was generally clean and well-maintained; nonetheless, several fire hazards existed. Each classroom door had a glass transom above it, which provided ventilation into the corridor but also permitted flames and smoke to enter once heat broke the glass. The school had one fire escape. The building had no automatic fire alarm, no rate-of-rise heat detectors, no direct alarm connection to the fire department, no fire-resistant stairwells, and no heavy-duty fire doors from the stairwells to the second-floor corridor. At the time, fire sprinklers were primarily found in factories or in new school construction, and modern smoke detectors did not become commercially available until 1969.