This weekend Jeff and I descend to the bottom of a cold and dripping sinkhole in Ontario, Canada. It would appear that most are unaware of the existence of these pits, thinking that they only occur in Florida and other places where there have been some well publicized swallowings of people and posessions. Sinkholes occur for several reasons, but in stable rock they develop slowly and predictably over thousands of years and it is only the careless who end up lying broken and dying at their bottom.
In Toronto, it is most likely an underground pipe that has broken and eroded the lake deposited sediment beneath the city streets that would pose a sinkhole hazard. On rare occasions there have been collapse windows that have unexpectedly appeared in farmer’s fields, and of course there have been the celebrated cave-ins around mining communities like Cobalt and Kirkland Lake that have resulted in the loss of buildings. I believe it was in Timmins that a school bus was swallowed up one night with a sleeping beggar who had sheltered there, little suspecting that he would wake up entombed within the earth.
I spend my weekends caving and it appears that for the scarcity of horizontal cave openings near Toronto, it is now the vertical shafts that we are breaking open in hopes of exposing buried tunnels. Pictured here is one such shaft that sinks deep into virgin rock.