THE 1988 MALDEN, MASSACHUSETTS LANDSLIDE: A CASE OF MULTIPLE HUMAN CAUSES OVER A CENTURY IN THE MAKING

On October 8, 1988, in Malden, Massachusetts, several hundred cubic yards of jointed granite toppled and slid onto a house. One large slab crashed through an exterior wall and into a bedroom, narrowly missing a mother and her two children. A vehicle was also destroyed with total losses estimated to be $375,000 (2012 dollars). Although a relatively minor slide, its history well-illustrates how poor decisions by a municipality and developers over a period of decades led to what, for one family, was an avoidable disaster not of their making.

Several meters behind the house a cliff in Dedham Granite rose to a height of 40 feet. The cliff is actually a quarry wall last worked about 1873, which explains its precarious, unnatural overhang. By about 1940 the quarry was partially filled and a street constructed through it. The house in question was built around 1980 and later sold to the person who owned it at the time of the slide. Two prominent joint sets are exposed in the cliff, one dipping steeply into the face to produce the overhang, and one nearly perpendicular to the first and dipping out of the face. An exposed joint surface of this latter set formed a ramp sloping toward the house down which the blocks slid subsequent to toppling.

A trace of rain fell the day before the slide but is not considered to be a major contributor. For two weeks prior to the slide a trackhoe-mounted hydraulic hammer was being used to excavate two building lots into the granite approximately 200 feet from the landslide. The possibility that ground vibrations from this work contributed to the slide were never investigated but may have been the trigger. Shortly after the slide the city amended its regulations on construction-related noise and vibrations. Had a geotechnical site-specific study been required with the application for a building permit, the destroyed house may never have been built. Permits to excavate the lots nearby using such extreme measures should never have been issued. After the 1980's real estate bubble burst, homes were never built on the two lots and the owner of the destroyed house did not recoup his losses.