Koridallos vocational school closed Thursday after propane alarm in lab

Gas alarm during lessons

On Wednesday, 11 November 2026, a gas detector in the silversmithing lab of the 1st EPAL Koridallos vocational high school went off during lessons. in.gr places the alarm around the fourth and fifth lesson periods on Wednesday morning, while NewsIT says it sounded during the final lessons of the day. According to the mayor, Nikos Choursalas, the system alerted the school's administration directly. NEWS 24/7 reports that the alarm rang amid a strong gas smell.

Under the safety protocol, the siren and beacon in the lab were activated, the gas solenoid valve closed automatically to cut the supply, and an air extraction fan started ventilating the room, SKAI reports. The propane supply, which feeds labs at the EPAL and at the SAEK Koridallos that shares the building, was shut while checks were pending, according to in.gr.

Accounts of how students left the building

Accounts differ on how students left the building. NewsIT says the school was evacuated under protocol and that evening classes were not held. NEWS 24/7 reports that students were taken to the schoolyard for about an hour without being told why, then returned to their classrooms where lessons continued, citing a parent who spoke to MEGA. in.gr says teachers moved students out of the classrooms.

Closure and remote teaching

The mayor's decision to close the school on Thursday, 12 November, came late on Wednesday evening, according to in.gr. Lessons for the roughly 800 students are held remotely on Thursday and will continue that way until checks by certified bodies are complete, SKAI reports. The mayor addressed the reopening conditions directly.

“What is important to communicate is that the system has worked and that no student or teacher will enter before the checks are completed so that everyone feels safe.”

Cause and next steps

The cause has not been confirmed. NewsIT says all signs point to a propane leak, but the investigation is continuing. Competent personnel are due at the school on Thursday to read the sensors, pinpoint the exact leak location and then carry out repairs to the supply, according to in.gr. NewsIT reports the gas detector was installed about 15 months earlier, while in.gr gives about a year and a half. NewsIT also links the event to a gas leak at a school in Grava that led thousands of students to remote learning and a temporary closure of that complex.