As a child , my parents and I lived in the closest home to the south of the portal and tunnel cut of the then electrified rail line passing under the St.Clair River to Port Huron Michigan. on the US side the rails were Pere Marquette . The locomotives used to transit the tunnel were electric , because a consist had come apart in the tunnel back around 1900 and the crew sent in to haul out the stranded cars by steam locomotive were asphyxiated while building a head of steam while trying to connect to the freight cars. At the time a simple pin and eyelet system was in use which was fine on normal flat horizontal pulls , but going into the tunnel the slope and gravity allowed the pin to fall out , thus the decoupling .
I have a ton of memories about the tunnel cut… sleighs and tobaggans in winter , the short cut to my earliest days in school , etc.