The Danger of Sinkholes

In the aftermath of an enormous sinkhole that swallowed a Quebec home, killing a family of four, officials are trying to determine how vulnerable communities in the region are to unstable leda clay.

On May 10th, an enormous millennia-old deposit of leda clay suddenly gave way beneath a home in the community of Saint-Jude, Quebec. A family of four watching TV in the basement were killed as the home was sucked up to its eaves in mud. Now communities in the region are concerned that they may be vulnerable to similar sinkholes, while some residents continue to engage in risky construction, such as swimming pools.

"Nervous residents of Saint-Jude have flooded the office of Mayor Yves de Bellefeuille. Saint-Jude was previously classified as being at low risk for a slide...Inspectors are scrambling to take soil samples along a stretch of the Salvail River where a deadly landslide killed a family of four, but experts say sensitive marine clay severely limits the level of assurance such tests can provide to residents.

[Quebec has] spent millions in the past five years making sure a chunk of the community of 7,700 doesn't slide into the Nicolet River. Several downtown blocks slumped in 1955, killing three people, destroying homes, businesses and a school and leading to the demolition of the town's church. [But] property owners often complicate matters. Many are fiercely protective of their right to dig a swimming pool or chop down an erosion-preventing tree...many owners insist their own properties are fine."

Full Story: Residents seek reassurance in wake of deadly slide



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Does this ever happen to homes built on fill?

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