SS Mont-Blanc was a cargo steamship that was built in Middlesbrough, England in 1899 for a French shipping company. On Thursday morning, December 6, 1917, she entered Halifax Harbour in Nova Scotia, Canada laden with a full cargo of highly volatile explosives. As she made her way through the Narrows towards Bedford Basin, she was involved in a collision with Imo, a Norwegian ship. A fire aboard the ship ignited her cargo of wet and dry 2,300 tons of picric acid, 500 tons of TNT, and 10 tons of guncotton. The resultant Halifax Explosion killed approximately 2,000 people and injured about 9,000.

Middlesbrough is a town in the Middlesbrough unitary authority borough of North Yorkshire, England. The town lies near the mouth of the River Tees and north of the North York Moors National Park. The built-up area had a population of 148,215 at the 2021 UK census. It is the largest town of the wider urban Tees Valley area, which had a population of 678,400 in 2021.