Galveston Island, as the area was not protected by the Galveston Seawall. The ferry from the island to the Bolivar Peninsula was closed, while voluntary evacuations were issued in Surfside in Brazoria County. When the National Hurricane Center issued the first advisory on Allison, officials issued Tropical Storm Warnings from Sargent, Texas to Morgan City, Louisiana. After the storm made landfall, flash flood watches and warnings were issued for numerous areas in eastern Texas. During the flood event, the National Weather Service in Houston issued 99 flash flood warnings with an average lead time of 40 minutes. With an average lead time of 24 minutes, the National Weather Service in Lake Charles, Louisiana issued 47 flash flood warnings. With an average lead time of 39 minutes, the National Weather Service in New Orleans/Baton Rouge issued 87 flash flood warnings, of which 30 were not followed by a flash flood. In Tallahassee, Florida, a shelter opened the day before Allison's movement northward through the area, seven staff members housing 12 people. Two other shelters were on standby. Teams informed citizens in the Florida Panhandle of flood dangers. Impact Tropical Storm Allison was a major flood disaster throughout its path from Texas to the Mid-Atlantic. The worst of the flooding occurred in Houston, Texas, where over of rain fell. Allison caused approximately $8.5 billion in damage (2001 USD), making it the costliest tropical cyclone that was never a major hurricane on record in the Atlantic basin. The storm also killed 41 people directly, including 27 who drowned. This ties Allison with a tropical storm in 1917 as the second-deadliest tropical storm to affect the contiguous United States, surpassed only by the 1925 Florida tropical storm which killed 73 people. Texas Combined with waves on top, areas of Galveston Island experienced a wall of water in height, creating overwash along the coastline. The storm caused winds of up to at the Galveston Pier. While Allison was stalling over Texas, it dropped very heavy rainfall across the state. Minimal beach erosion was reported. Flash flooding continued for days, with rainfall amounts across the state peaking at just over in northwestern Jefferson County. In the Port of Houston, a total of was reported. Houston experienced torrential rainfall in a short amount of time. The six-day rainfall in Houston amounted to . Houston Hobby Airport received 20.84 inches of rain from June 5 to 10, 2001,