A gas leak explosion devastated an HLM building in Trévoux, Ain, killing two children aged 3 and 5 named Mathieu and Thomas. The parents and older brother survived, while thirteen people were injured and about thirty others shocked. The prefecture activated the Novi plan to manage the crisis.
On Monday, December 15, 2025, around 5:30 p.m., a powerful blast echoed through Trévoux, a small town of 6,930 residents located about 25 miles north of Lyon. The explosion, caused by a gas leak from a boiler, demolished the ground floor of a four-story HLM building in the Beluizon neighborhood, without causing it to collapse.
The family living in the apartment was present at the time of the disaster. The two youngest sons, Mathieu (5 years old) and Thomas (3 years old), perished despite resuscitation attempts by rescuers. The older brother and parents survived, though severely shocked. “We helped get the mother out; she was in shock, desperate,” testified a young neighbor. The father had to identify the bodies, a devastating ordeal according to another resident.
The toll includes thirteen injuries: ten in relative emergency transported to the hospital, and three minor. About thirty people, including residents from the building housing around 70 inhabitants, received care for psychological shock. A medico-psychological emergency unit was established. Mayor Marc Péchoux activated the communal safeguard plan, housing nearly 50 people in a gymnasium overnight.
Ain’s prefect, Chantal Mauchet, visited the site and triggered the Novi plan, or “ORSEC-Multiple Victims,” to coordinate rescue and logistics. Fifty firefighters, 36 vehicles, and 45 gendarmes were deployed, with dog teams searching the debris for potential other victims. “The firefighters are still at work,” said Colonel Pierre-Maris Grandcolas of the SDIS.
The blast was heard several miles away, shattering windows in two nearby schools, with no injuries reported among students. A local football club educator, where one child was enrolled, was seen crying on site. Interior Minister Laurent Nuñez expressed condolences on Twitter. An investigation was opened by the Bourg-en-Bresse prosecutor to determine exact causes, though a gas emergency truck was observed.
Trévoux’s community is in shock, ten days before Christmas. “They are children from my son’s class; I don’t know how I’ll tell him,” confided a mother.
