The wetlands of the coastal Louisiana have been disappearing at an alarming rate. The rate was further accelerated during the Hurricane Katrina. Hurricane Katrina converted a large area of wetland into open water by bulk removal of vegetation, flooding, and killing of plants through the salt water inundation. The aim of this study was to quantify wetland loss rates in a high salinity wetland of St. Bernard Parish, Louisiana before and after Hurricane Katrina made landfall. Change-detection-mapping and analysis, using Landsat TM images, was used for generating the change matrices. Images from 1990 and 2010 were analyzed to estimate total wetland loss and the wetland loss contributed by Hurricane Katrina over the 20-year period. The analysis revealed that wetland loss in the study area during Hurricane Katrina accounted for over half (65%) of the total land lost over a 20-year period (1990 to 2010). The annual net loss of wetland to water during 2003-2004, 2004-2005 and 2005-2006 were estimated to be 10.82 km², 15.42 km² and 36.06 km² respectively, which is 26.45 %, 24.80% and 48.76% of total changes in four years (2003-2006). Vegetation disturbances were mapped using Normalized Difference Vegetation Index (NDVI).