In Castle Village Owners Corp. v. New York Mutual Insurance Co., a retaining wall on plaintiff’s property collapsed, causing tons of dirt and debris to fall on the adjacent roads, including the Henry Hudson Parkway. As a result, Parkway had to be closed, and passing automobiles and adjacent property were damaged. The City of New York immediately ordered remediation steps, including stabilization of the wall, additional protection from rainwater, and a temporary means of protecting vehicles. The plaintiff sought coverage from its liability excess carrier (the primary policy was exhausted in paying the damage claims). New York Mutual disclaimed coverage for remediation under the “own property” exclusion contained in the policy. Because there was no imminent threat of damage to other property, there was no coverage.

http://www.nycourts.gov/reporter/3dseries/2009/2009_03625.htm