( CNN ) -- A gap in communication between the National Weather Service and the Army Corps of Engineers undercut forecasts of the deadly flood that struck middle Tennessee in 2010 , the National Weather Service reported Wednesday . The Corps of Engineers was forced to increase the flow of water from a dam on the Cumberland River amid record rainfalls over Nashville and the surrounding region on May 2 , according to a newly released National Weather Service review of the disaster . But forecasters were n't told about the additional releases , and the Cumberland passed its predicted crest of 41.9 feet within two hours of their advisory , the report states . `` If they had been able to provide that data back to the Weather Service , we could have had a better chance of producing a more accurate and timely forecast for the Cumberland River , '' said Weather Service meteorologist Jane Hollingsworth , the report 's author . `` But again , because of the rapid evolution of the event , we could not create that communication exchange . '' The Cumberland eventually crested at nearly 52 feet in downtown Nashville , nearly 12 feet over flood stage . The resulting flooding killed 11 people in the city and inflicted more than $ 2 billion in damages , with another 15 people killed in the surrounding region . Both Hollingsworth and Jack Hayes , the Weather Service 's director , emphasized that the communication breakdown occurred during an `` unprecedented '' situation , when two-day rainfall totals more than doubled their previous record . The Corps had to increase water flows at the Old Hickory Dam in Hendersonville `` to protect the structural integrity of this dam , '' Hollingsworth told reporters . In its own November assessment , the Corps of Engineers acknowledged that `` misunderstandings '' between its Nashville district office and the Weather Service threw off forecasts `` to some degree . '' Lt. Col. Anthony Mitchell , the district commander , told CNN that the Weather Service 's report was `` pretty fair '' and consistent with the Corps ' own report . `` Obviously , our normal protocols in how we would communicate were taxed , and they were taxed to a degree that we recognize that we need to improve upon , '' Mitchell said . But , he added , `` Our actions and the actions of those Corps employees that were out there on the spillway gates , making adjustments , saved those projects and saved lives as well . '' The Corps is working on ways to share real-time data with forecasters and other agencies that need it , he said . Hollingsworth said that while the Weather Service issued flood warnings , many residents of the affected areas said they could not relate those warnings to the impact on their neighborhoods . As a result , she said , `` All perceived that they had no warning . '' Hayes said the Weather Service , the Corps of Engineers and the U.S. Geological Survey have taken steps to improve communication and to learn more about each others ' operations in the wake of the event . And he said the service has developed forecast maps that relate predicted crests to maps , allowing residents to see a clearer picture of how far floodwaters will reach . `` They need to know , when the river reaches 48 feet , what that will mean for their homes and businesses , '' Hollingsworth said . CNN 's Dave Alsup contributed to this report .
Forecasters did n't know about the runoff from a dam upstream , the report finds . The Weather Service and the Corps of Engineers say they 're working to fix the problems . The May 2010 floods killed 26 people and flooded downtown Nashville .