The danger of life-threatening inundation from storm surge persists in Central Florida as a revived Hurricane Ian crashed into South Carolina on Friday.Ian’s center came ashore near Georgetown, South Carolina, with much weaker winds than when it crossed Florida’s Gulf Coast on Wednesday as one of the strongest storms to ever hit the U.S. As it moved across South Carolina, Ian dropped from a hurricane to a post-tropical cyclone. Sheets of rain whipped trees and power lines and left many areas on Charleston’s downtown peninsula under water. Four piers along the coast, including two at Myrtle Beach, collapsed into the churning waves and washed away. Ian made its first landfall Wednesday afternoon near Cayo Costa, Florida, as a Category 4 storm with winds of 150 mph. Hours after weakening to a tropical storm while crossing the Florida peninsula, Ian regained strength Thursday evening over the Atlantic. Ian made landfall in South Carolina with maximum sustained winds of 85 mph. Ian left a broad swath of destruction in Florida, flooding areas on both of its coasts, tearing homes from their slabs, demolishing beachfront businesses and leaving more than 2 million people without power.During a press conference Thursday morning, Gov. Ron DeSantis noted that Central Florida is experiencing "a 500-year flood event." Speaking Friday morning, officials said there have been up to 21 reported deaths. Two deaths have been recorded in Central Florida, both in Volusia County.One man died in DeLand while trying to drain his pool, and another drowned as floodwaters rose.Chopper 2 was over Orlando, where we saw tremendous flooding in the area. Why did Ian hit Central Florida so hard?The shocking images showing the devastation caused by Hurricane Ian have been stunning, and many might be wondering how this storm caused such widespread damage across the state of Florida despite it getting weaker.First Warning Weather Meteorologist Alex Alecci said Ian was moving fairly slow after making landfall at near Category 5 status in southwestern Florida."It just had so much rain to dump," Alecci said. "And while it hit Fort Myers as a Category 4, almost even a Category 5, that's a lot of momentum of winds and spin. So it has to wind itself down."Ian had plenty of strength and power as it move through the Florida peninsula, but it was what happened on the other side of the peninsula that created a damaging effect."It starts wrapping all that Atlantic moisture back on to shore," Alecci said. "So you get the storm surge issues as well up there. As the storm surge pushes up along the coast, most of the rivers and most of the drainage systems drain out towards the ocean. While the ocean is piling up against those pipes, it just can't drain out."WATCH: Stunning videos shows Central Florida hit with punishing winds, flooding rainsWESH 2's Tony Atkins rescues woman who attempted to drive through floodwatersFlooding at Disney resort during Hurricane IanFamily grateful to be alive after tree falls on house during IanWild video shows rough hurricane hunter flight into IanRelated: Video shows men wading through Hurricane Ian floodwaters in Key West