After Superstorm Sandy struck the northeast U.S. in 2012, an unprecedented effort began to fortify the densely populated coastline against the next big storm.Thousands of homes were raised on pilings. Concrete and steel walls meant to help hold back the sea were hidden beneath rebuilt dunes and beach boardwalks. Tunnels near New York’s harbor were equipped with giant flood doors.Then, last year, the region learned that even all those precautions might not be enough in an age of more powerful storms.Flash floods killed at least 58 people from Maryland to Connecticut when the remnants of Hurricane Ida blew into the northeast after first striking the Gulf Coast. In New York and New Jersey, people drowned in basement apartments far from any ocean or bay. In the suburbs, motorists were swept away trying to escape flooded inland roadways.The two deadly storms, nearly a decade apart, left public officials and residents alike contemplating what more needs to be done. And today, 10 years after Sandy and with billions of dollars already spent, the most ambitious and comprehensive protections are years away from completion, with some still in early stages or even unfunded. Experts say Ida showed the area was not ready for another storm – and they worry about what will happen when the next one hits.’We must be more prepared than we are now,’ said Shawn LaTourette, New Jersey’s environmental protection commissioner. ‘We have done a lot of work since Sandy – developing the dune system, the buildings raised and the flood control infrastructure. We’re still not ready.’Residents echo his concerns. ‘I will be forever nervous because of Sandy,’ said Liz Ndoye, whose Hoboken home flooded. ‘I will never feel safe. We can mitigate, but we will never stop the city from flooding. Every time it rains, I worry. We are in a climate crisis.”She watched Hurricane Ian devastate the Florida coast weeks ago. “This is coming for all of us,’ she said of future storm fears. Experts nationwide say hurricanes like Ian set off a familiar cycle: Another round of evaluations follows each storm, adding to the list of needed work, from the overhaul of aging inland stormwater management systems to infrastructure projects to address climate change concerns. ‘We have to think of more sustainable ways to live along the coast,’ said Greg Tolley, executive director of the Water School at Florida Gulf Coast University. ‘We have to do things differently. The so-called 100-year storms and the Category 4 and 5 hurricanes are happening more frequently.’When Sandy made landfall just north of Atlantic City on Oct. 29, 2012, it touched off a rethinking on not just rebuilding the region, but on the effect of a warming planet and rising seas for all plans. In New York, work began last year on a $1.5 billion effort to protect Manhattan’s Lower East Side by raising the East River shoreline about 8 feet. The project involves bulldozing around 1,000 trees and a waterfront park, then rebuilding it and a 1.2-mile-long (1.9 kilometer) floodwall on top of tons of fill. It’s one phase of a ring of planned flood barriers and levees dubbed ‘The Big U.’ Completion isn’t expected for years.The project proceeded despite criticism that it cut too many mature trees. It’s a common concern among environmental advocates and other experts: Each project may offer a solution to a singular issue while creating new problems, especially where climate change is involved. ‘Because the challenges we face are very widespread and can vary – they might deal with something like long-term sea level rise or being prepared for a big storm shock like Sandy – I think we’re at real risk of it showing up in a slightly different way, and we won’t have the defenses in place to handle that,’ said Andrew Salkin, who co-founded New York-based nonprofit Resilient Cities Catalyst.”Solely relying on hard infrastructure and gray infrastructure, like concrete and steel, to erect things to keep out nature is challenging,’ he said. ‘Over time, nature tends to win.’Last month, the U.S. Army Corps of Engineers unveiled a $52 billion proposal to build tidal gates and storm surge barriers to protect parts of New York and northern New Jersey. Construction would start in 2030 at the earliest, with projected completion in 2044 if all is approved and funded.The Army Corps has a separate $16 billion plan to build gates that could stop storm tides from surging up inlets and bays behind the Jersey Shore. It would be one of the costliest flood-prevention projects any state has undertaken, and there’s no guarantee Congress will pay for any of it.Some projects launched after Sandy are complete. A 4-mile (6.4 kilometer) steel wall is buried under the sand of replenished beaches in Mantoloking and Brick at the Jersey Shore, where storm surge cut a coastal highway in half and swept dozens of homes into Barnegat Bay.The Jet Star roller coaster – whose collapse into the ocean at Seaside Heights, New Jersey, became an iconic Sandy image – has been replaced with a new ride, built on the beach instead of over water.A New Jersey train station where floodwater gushed in through an elevator shaft has been rebuilt with aquarium glass and flood doors that can be slammed and locked in less than a minute.And billions of dollars have been spent hardening power infrastructure, ringing water and sewage treatment plants with better storm barriers, and elevating home electrical, heating and cooling equipment.Officials admit the scope of that work is vast but say it’s a fraction of what remains. ‘Are we better off than we were before Sandy? No question,’ said LaTourette, the New Jersey official. “But it’s not enough.’Complicating the calculus of storm protection was Hurricane Ida – a ‘humongous wakeup call,’ said Amy Chester, managing director of Rebuild by Design, an organization that worked with federal officials to jump-start post-Sandy resiliency projects. ‘It showed us that every single community can flood, not just those in flood plains,’ she said. The group says urban areas need to be transformed from concrete jungles into sponges by creating ‘resiliency parks’ designed to flood during storms. The parks capture water that would otherwise flow into streets and sewer systems.The city of Hoboken built two such parks after Sandy, with three more to come. They can hold millions of gallons of stormwater, some via large underground cisterns, one of which is the size of a city block. New York has begun some work to improve inland drainage, including spending $2.5 billion to upgrade antiquated sewers, though many billions more in spending would be needed to make the system capable of handling storms like either Sandy or Ida. In the Bronx, the city hopes to take a brook diverted into the city’s sewer system a century ago and bring it back above ground. That might help avoid a repeat of issues during Ida: The brook, swollen beyond capacity of the sewer pipes, ran onto a major city expressway and submerged cars.Other work that began after Sandy and continues today includes six projects sponsored by Rebuild by Design and funded in part by nearly $1 billion in federal seed money given in 2014. ‘The Big U’ is among them. So is a resilient energy generation project in the Bronx and a plan to lessen flooding in northern New Jersey’s Meadowlands. Other projects are in Hoboken and Bridgeport, Connecticut.Some aspects of the largest projects could be completed next year, while others will take years more to finish.’Am I happy with the pace? No,’ Chester of Rebuild by Design said. ‘But it is reality that it’s going to take time to get our cities prepared for future storms. One thing we quickly realized is just how complex these projects are.’At a groundbreaking Wednesday for one segment of ‘The Big U,’ New York Mayor Eric Adams asked the federal government for another $8.5 billion for future storm-protection projects.’Sandy wasn’t just a storm; it was a warning,” he said, echoing officials’ comments over the past decade. ‘Another storm could hit our city at any time.’ And each storm is likely to bring more plans and adaptations. Florida has been forced repeatedly to rethink its resiliency goals, from stronger construction codes adopted after Hurricane Andrew in 1992 to a $1 billion plan approved last year to help communities build barriers, elevate roads, improve drainage and protect wetlands.Tolley, the Florida educator, said Ian proved the need for urgency in all states’ plans: “We need to have that conversation now about what we have to do and what things should look like 20, 30, 40 years from now.’In New Jersey, LaTourette agrees.’The Sandys and the Idas will keep coming and they’ll keep getting worse,” he said. ‘We have to get better at doing what we always say we’ll do: Look at things from the perspective of what we leave our kids. We decide whether the barrier islands are still there for them in their retirement,’ LaTourette said. “We’re deciding that now.’___AP writer Bobby Caina Calvan in New York contributed to this story.Follow Wayne Parry on Twitter at www.twitter.com/WayneParryAC