30 percent of Galveston's population evacuated the island when Hurricane Allen threatened the eastern Texas coastline in 1980; only 10 percent of the population living behind the seawall chose to leave when Alicia made landfall. Throughout the day, however, as increasing winds began to cause damage in Galveston, people grew more worried. The mayor finally ordered a widespread evacuation of the island after midnight on August 18, but by then the bridges to the mainland were no longer usable as they have been broken.