Hurricanes bring destruction ashore in many different ways. When a hurricane makes landfall, it often produces a devastating storm surge - ocean water pushed ashore by wind - that can reach 20 feet (6 meters) height and moves several miles inland. Storms surges and flooding are the two most dangerous aspects of hurricanes, accounting for three-quarters of deaths from Atlantic tropical cyclones, according to a 2014 study. A third of the 1,200 deaths from Hurricane Katrina, which made landfall off the coast of Louisiana in 2005, were caused by drowning. Katrina is also the costliest hurricane on record, with damage totaling $125 billion. A hurricane’s high winds are destructive and may spawn tornadoes. Torrential rains cause further damage via flooding and landslides, which may occur many miles inland. Although extremely potent storms have formed in the Atlantic, the most powerful tropical cyclones on record have formed in the Pacific, which gives storms more room to grow before they make landfall. Hurricane Patricia, which formed in the eastern Pacific off Guatemala in 2015, had the strongest winds recorded, at 215 miles an hour. The strongest Atlantic storm was Wilma in 2005, with winds of 183 miles an hour. The best defense against a hurricane is an accurate forecast that gives people time to get out of the way. The National Hurricane Center issues hurricane watches for possible storms within 48 hours and hurricane warnings for expected storms within 36 hours.