The Hogg’s Hollow Disaster on March 17, 1960, killed five Italian immigrant workers: Pasquale Allegrezza, Giovanni Correglio, Giovanni Fusillo, and brothers Alessandro and Guido Mantella. They were clearing a tunnel 35 feet below ground to create overflow ditches after Toronto’s Hurricane Hazel. They had no hard hats, fire extinguishers, or resuscitators; they were working in a tunnel six feet in diameter, and had to crawl under a 36-inch watermain to pass each other.
Soft tunnelling conditions required the use of air pressure many times higher than normal to stop cave-ins and the entry of dirt and silt. The first contractor with a winning (but unrealistically low) bid went broke, and the bonding agency that took over the contract speeded up the work; extended the pressurized parts of the tunnel; and ignored numerous fires in the oxygen-rich environment.
The tragedy occurred when a spark from a cutting torch ignited a rubberized cable and the five men were trapped behind a wall of poisonous smoke. The air pressure was cut off, causing a cave-in of silt and water. Autopsies determined deaths by drowning and carbon monoxide poisoning.
This disaster was quickly followed by strikes for union recognition by Italian immigrant construction workers in Toronto. Toronto’s Italian community and the labour movement responded to support the labour disputes by organizing a rally of 17,000 construction workers on June 26, 1961 at the CNE Stadium. The activism of the community and the labour movement led to a Royal Commission on health and safety, and, ultimately, new legislation to protect workers.