National Guard trucks carry rescued residents through floodwaters to the Superdome on Aug. 30, 2005, a day after Hurricane Katrina hit in New Orleans. AP Photo/Eric GayHurricane Katrina looms large in the history of American emergency management, both for what went wrong as the disaster unfolded and for the policy changes it triggered.As the nation looks back on the disaster 20 years later, I believe as a crisis and emergency management specialist that it is more important than ever to remember Katrina’s lessons to avoid repeating past mistakes.When Katrina hit New Orleans on Aug. 29, 2005, its storm surge broke through levees protecting the city. Water quickly poured into low-lying neighborhoods, flooding houses up to their rooftops and inundating an estimated 80% of the city. People who could not evacuate before the storm and were lucky enough to escape to their roofs were stranded for days in some cases.Once the water had receded and the death toll counted, it became clear that nearly 1,400 people had died as a result of this devastating storm. The hurricane did more than $100 billion in damage, equivalent to about US$170 billion today when adjusted for inflation. Helicopters rescue stranded residents from rooftops on Sept. 1, 2005, three days after the hurricane. AP Photo/David J. Phillip While there were many unsung heroes during Katrina, the tragic missteps and missed opportunities at all levels of government emergency management are what no emergency manager ever wants to repeat. The response failed in many areas, from broken communications among federal, state and local agencies to the reported horrors in the Superdome as 16,000 evacuees faced failed generators, poor security, dwindling supplies and overflowing toilets.Three lessons from Katrina stand out today as the Trump administration talks about dismantling the Federal Emergency Management Agency and putting more responsibility for disaster management on local and state agencies. 1. Emergency response is only as strong as the weakest linksFEMA took the brunt of the criticism after Hurricane Katrina. However, serious analyses of what went wrong recognize that good disaster response requires effective governance at all levels.Before FEMA could spend significant money to deploy people and aid, the state of Louisiana had to request a presidential disaster declaration. However, tensions between the state and federal governments reportedly delayed President George W. Bush’s approval, according to a Senate committee report assessing the response. The committee also found that New Orleans Mayor Ray Nagin’s decision to first issue a voluntary evacuation and not issue a mandatory order until a day before the storm cost precious time. New Orleans Police Superintendent Eddie Compass tells people in front of the New Orleans Convention Center on Sept. 2, 2005, that they will get food and water. A heavily armed military convoy arrived in hurricane-devastated New Orleans that day, four days after the hurricane, with urgently needed supplies. Robert Sullivan/AFP via Getty Images Once the storm hit, communication and coordination fell apart.Vehicles badly needed for the disaster response were damaged by the storm. Problems with communication systems and a breakdown in situation reporting from local law enforcement and rescue services left state and federal government decision-makers flying blind, without up-to-date reports of conditions on the ground. Media reports of a “war zone” in New Orleans exaggerated the extent of public disorder and threats to responders. That further delayed the arrival of federal military and National Guard assistance – and hindered some local efforts – because it required additional precautions for coping with a hostile security environment. As challenging as the information environment was during Hurricane Katrina, it is more difficult now. Social media, hyper-partisanship and deliberate misinformation attempts complicate emergency response and recovery efforts.If the federal government now proposes to push more responsibility for disaster relief to the state and local levels, emergency managers at those levels will be taking on highly complex disasters in a potentially toxic information environment with less support.States, counties and cities vary greatly in their readiness to shoulder this responsibility.2. Leave no one behindAn enduring image of Hurricane Katrina was the plight of residents who lacked transportation and took shelter at the New Orleans Superdome, where conditions quickly deteriorated.Another was the harrowing tales of gravely ill patients and exhausted medical staff stranded at Memorial Medical Center for five days without power as temperatures rose and the lower floors flooded. A volunteer who used his boat to rescue several residents from a flooded east side New Orleans neighborhood carries a man who could not walk to safety on Aug. 31, 2005, two days after the storm. AP Photo/Eric Gay These extreme predicaments and the deaths of people trapped in flooding homes in the Lower Ninth Ward were powerful reminders of the vulnerability of many low-income, elderly and ill residents who were unable to get out ahead of the disaster.A few years after Katrina, Obama administration FEMA Administrator Craig Fugate and his team placed a new focus on forging a “whole community” emergency management strategy. It is designed to include marginalized populations in emergency planning and ensure that those who aren’t able to evacuate due to disability or financial limitations are not forgotten during disasters.Government guidance now states that emergency mass care shelters be in buildings that people who have trouble walking can navigate easily. Emergency information is typically distributed in multiple languages, accessible for people with impaired hearing or vision, and written in ways adapted to the cultures and circumstances of minority groups. Hurricane Katrina victims wait for transportation at the convention center in New Orleans on Sept. 1, 2005. AP Photo/Eric Gay However, many of these advances are in jeopardy today as the Trump administration seeks to eliminate initiatives that might be considered DEI – diversity, equity and inclusion. The misery and death caused by Hurricane Katrina should serve as vivid reminders of why many existing emergency management programs emphasize the needs of socially vulnerable populations.3. Professional emergency management is essentialThe face of the federal government’s shortcomings in responding to Hurricane Katrina was then-FEMA Administrator Michael Brown. Initially, he was publicly praised by President Bush, who declared: “Brownie, you’re doing a heck of a job!”But Brown was not a professional emergency manager. His prior on-the-job experience in the role did not prove sufficient in this extreme situation. As the problems with the response to Katrina became increasingly evident, Brown proved unable to provide effective leadership in the crisis and was forced out. FEMA Administrator Michael Brown, center, updates President George W. Bush, left, on the aftermath of Hurricane Katrina on Sept. 2, 2005. Jim Watson/AFP via Getty Images Part of the legislative legacy of Katrina is the Post-Katrina Emergency Management Reform Act of 2006. It requires that FEMA chief administrators have extensive knowledge of emergency management and substantial relevant executive leadership experience. All of the subsequent confirmed heads of FEMA were once state emergency management directors or had been in charge of emergency management in major cities.However, those requirements do not always apply to acting administrators. In his second term, President Donald Trump has had two acting FEMA administrators – Cameron Hamilton and David Richardson. Both lacked prior experience managing major disasters on a statewide or comparable basis. Hamilton was abruptly fired after suggesting to Congress that FEMA should not be eliminated. Richardson’s leadership was quickly tested during the Texas flash flood tragedy on July 4, 2025, that killed more than 135 people.The shortcomings of the response to Hurricane Katrina also led to wider adoption of the National Incident Management System, which helps all levels of government, nongovernmental organizations and the private sector work together in an emergency.If more responsibility for emergency management devolves to states in the future, they will need to cultivate the ability to coordinate and collaborate effectively to respond to disasters.Looking aheadLeaders and organizations such as FEMA have learned from crises such as Hurricane Katrina.However, political priorities come and go, staff turns over, and generations pass the torch to their successors. Leaders and organizations can forget critical lessons from the past.As efforts to reform – and possibly rebalance – the U.S. emergency management system continue during the Trump administration, it is essential to remember and heed the costly lessons of Hurricane Katrina.Eric Stern has recently received funding from DHS Science and Technology for an extreme weather informatics project and from NOAA for work on extreme heat events. He has lectured at the National Emergency Management Executive Academy and many similar programs around the country and the world.