Algoma Steel Group Inc.

Structural Corridor Collapse

On January 20, 2024, a structural corridor carrying various utilities crucial for the Company’s coke oven battery and blast furnace operations suffered an unexpected collapse. An independent investigation revealed an unforeseen escalating overload condition, resulting in a failure of a structural support member of the utility corridor, thereby causing the subsequent cascading collapse of other support structures. The collapse disrupted the flow of coke oven gas from the batteries to the rest of the steelworks, as well as a portion of the natural gas and oxygen flow to specific facilities, most critically the blast furnace. The unforeseen structural collapse did not result in any injuries, but for safety reasons, various areas near the collapse were evacuated and blast furnace operations were suspended at the time of the incident. Due to the unexpected shutdown and delayed restart, the blast furnace experienced operational challenges culminating in a chilled hearth, which suspended production for a period of three weeks, during which roughly 150,000 tons of hot metal production was lost.

The Company has standard insurance coverage that is intended to address events such as these, including business interruption and property damage insurance. The Company has engaged its insurers and has submitted claims under its insurance policies for covered losses.

The Company and its insurers continue to review the impact of the structural collapse and subsequent lost production as it relates to the insurance claim. During the three and twelve month periods ended December 31, 2025, the Company received insurance proceeds totalling C$25.0 million and C$75.0 million, respectively, which have been presented in other income in the consolidated statements of net loss. During the three and nine month periods ended December 31, 2024, the Company received insurance proceeds totalling nil and C$32.1 million, respectively.