Four Hospitalized After Gas Explosion Rips Through Nagoya Housing Complex, Authorities Probe Leak Source

Nagoya, Japan— A gas leak explosion tore through a three-story apartment building in Naka ward, Nagoya, at around 5:50 a.m. Tuesday, injuring four residents and blowing out windows across two floors as neighbors fled in the dark.

The blast originated in a second-floor unit on the north side of the building. According to the Nagoya City Fire Department, gas had accumulated overnight due to a faulty connection on a kitchen stove. When the occupant turned on a light switch, the spark ignited the gas. The explosion collapsed an interior wall and sent debris into the hallway.

Four people were injured. Two suffered burns and were transported to Nagoya University Hospital. The other two, including a child, sustained cuts from shattered glass and smoke inhalation. None of the injuries were described as life-threatening. Firefighters said the building's wooden frame limited the blast's spread but increased fire risk immediately after.

Fire crews arrived within six minutes and found the second floor engulfed in light smoke. They shut off the building's main gas valve and ventilated the structure with fans. No secondary fire developed. A total of 32 residents from 12 units were evacuated to a nearby community center. The city provided blankets and temporary masks.

The building, constructed in 1982, uses city gas supplied by Toho Gas Co. The utility company dispatched an emergency team to test pressure levels and inspect the meter. A spokesman said the building had passed its last scheduled inspection two years ago. He declined to comment on whether the stove connection was part of that inspection.

"I woke up to a loud boom. The whole building shook," said a 54-year-old woman who lives on the third floor. "I opened my door and saw smoke. I could not see the stairs." She escaped through a rear balcony with help from a neighbor. Several residents reported smelling gas late Monday night but assumed it was from outside.

Nagoya City's housing safety division issued an order Tuesday afternoon barring entry to the building until structural engineers complete an assessment. The blast damaged load-bearing elements near the stairwell. Temporary shoring was installed. Residents are not allowed to retrieve belongings until cleared. The city said it will arrange hotel vouchers.

Police and fire investigators are jointly handling the case as a suspected accidental gas explosion. They have recovered the stove and its rubber hose for laboratory analysis. The focus is on whether the hose was degraded or improperly fitted. A similar incident in Nagoya last year prompted a city-wide advisory about replacing old gas hoses.

The inspection will continue Wednesday. Utility crews will check neighboring buildings on the same line for leaks.