On October 29 and 30, 2012, Hurricane Sandy caused extensive destruction in the borough, ravaging portions of Lower Manhattan with record-high storm surge from New York Harbor, severe flooding, and high winds, causing power outages for hundreds of thousands of city residents and leading to gasoline shortages and disruption of mass transit systems. The storm and its profound impacts have prompted the discussion of constructing seawalls and other coastal barriers around the shorelines of the borough and the metropolitan area to minimize the risk of destructive consequences from another such event in the future. Around 15 percent of the borough is considered to be in flood-risk zones.