A cause has not been determined, but the federal transportation safety agency has characterized it as a natural gas explosion.

Source: https://abc11.com/pa-chocolate-factory-explosion-survivor-fell-vat-arm-on-fire/13057833/

A huge cooking gas explosion at a barbecue restaurant in north-west China has killed 31 people and left seven injured.

Source: https://metro.co.uk/2023/06/22/china-school-students-among-31-killed-in-restaurant-gas-explosion-18994047/

A state of emergency was also declared in September 2018 for the Merrimack Valley gas explosion.

Source: https://www.bostonherald.com/2023/08/08/gov-healey-to-announce-action-on-massachusetts-emergency-shelter-system/

Emergency services race to attend reported 'gas explosion'

Source: https://www.derbytelegraph.co.uk/news/derby-news/allestree-mum-who-miscarriage-doing-8811219

In particular how he and the regiment had been sent to Dortmund, in Germany, on a rescue mission after a massive gas explosion had devastated the area.

Source: https://www.kentonline.co.uk/gravesend/news/tribute-to-war-vet-who-lived-in-the-same-road-his-entire-lif-291606/

Phone footage shows house gas explosion aftermath.

Source: https://www.bbc.co.uk/news/uk-wales-64941189?at_medium=RSS&at_campaign=KARANGA

The mayor of Marseille said a parallel could not be drawn while the prosecutor said the buildings that collapsed on Sunday were not known to have any structural problems, and that a gas explosion is being investigated as a possible explanation.

Source: https://www.perthnow.com.au/news/disaster-and-emergency/fifth-body-recovered-from-collapsed-french-buildings-c-10308829