By Cassandra Garrison and Dave Graham

Hurricane Otis not only devastated Acapulco, but also exposed fatal weaknesses in ageing infrastructure, teaching hard lessons that coastal cities throughout Mexico must draw on.

As Acapulco rebuilds after the deadly Category 5 hurricane, climate experts, architects, engineers and politicians recommended steps Mexico should take.

These include tougher building standards, improving flood water management and enhancing storm detection to avoid repeating the death and destruction that Otis caused on Oct. 25.

Rising concern about climate change and increased proliferation of ultra-powerful storms has put pressure on Mexico, a top global tourist destination, to provide better protections, especially as coastal areas grow in population.

"Because these hurricanes are going to keep coming," former Mexican Tourism Minister Enrique de la Madrid said, these tasks lie ahead: "How do we build more intelligently, and also how do we adopt policies to combat climate change?"

He noted that after the 1985 Mexico City earthquake killed thousands, the capital imposed tougher building standards. As a result, there was far less damage 32 years later when another major quake hit the capital.

While Mexico City must update its standards for structural design every six years, Mexico lets other individual municipalities issue their own construction regulations. It lacks national rules, unlike regional peers.

A 2019 government map showed swaths of coastal states Oaxaca, Tamaulipas and Guerrero - Acapulco's home state - with no regulations at all. Acapulco does have its own.

After Otis, President Andres Manuel Lopez Obrador has called for an analysis of the city's buildings. His office did not respond to a request for comment on this story.

Adrian Pozos, a structural engineer at the National Autonomous University of Mexico, said Otis showed building and design norms were no longer up to the job.

He studied the impact of Hurricane Odile, a Category 4 storm that ravaged tourist resorts in Baja California state in 2014.

While Acapulco suffered far greater damage, Odile also made short work of lighter building materials including drywall, and destroyed communications towers, he said.

When such parts detach, interiors are left exposed, causing more damage. Debris can turn into dangerous projectiles battering other buildings, Pozos said.

After Odile, Baja California's building standards reflected new guidance on areas of weakness identified, such as roofs.

To avert disasters, it is vital that other beach towns, including Zihuatanejo, Puerto Vallarta and Cancun, pay special attention to metallic structural elements, he said. These are prone to corrosion in the salt air that reduces wind resistance, he explained.

Buildings need input from structural engineers to improve safety, he added, urging authorities to update wind regulations in coastal areas, particularly for buildings more than 10 years old.

New construction should be built to resist winds like the 329kph gusts that Otis blew, Pozos said.

Commercial buildings such as hotels and condos on parts of the Pacific coast should be built to absorb 214kph winds at most, and in Acapulco, 141kph winds, according to recommendations in a 2020 design manual from Mexico's state power utility.

In Miami, the American Society of Civil Engineers calls for comparable structures to resist 290 kph winds.

President Lopez Obrador has unveiled a $3.4-billion Acapulco recovery plan, and said the city should notice a difference by Christmas.

Some experts fear a full recovery could take years. David Waggonner of architecture firm Waggonner & Ball in New Orleans, which was battered by the devastating Hurricane Katrina in 2005, said disaster zones can re-emerge stronger.

Waggonner helped design a water infrastructure system to ease pressure on New Orleans' pumps and levees after Katrina, and said studies should assess how Acapulco handles water.

His plan, deployed in parts of New Orleans, retains and stores water instead of pumping it out.

Implementing an improvement plan in Acapulco, however, would only be half the battle, Waggonner said. Major commitments are needed to maintain the systems protecting coastal cities.

"To support the mechanism, the levees, the pumps and all things that are involved with a hurricane defence system, you have to have more money," Waggoner said. "Because it's a continual reinvestment."