As it often goes in Mexico, it is not the law that is problematic, but rather the implementation. Whether because of a lack of political will, the corruption that seethes through the system or the dysfunction of the bureaucracy, one of the deadliest threats that the nation faces has been left unfixed. Once the dust settles, officials will be confronted once more with a choice: whether to truly enforce a public safety imperative or continue with reforms that seem to exist mostly on paper.

“Some developers have their preferred inspectors and they usually hire the same person for their buildings, so that inspector is active, familiar, and always has a ton of work,” said Jorge Ortiz, an engineer and architect who is one of several hundred contract inspectors for the city. “And sometimes if you have several projects, they aren’t there as much or are not present at all phases of construction and that’s when there’s carelessness.”

According to last year’s study, of the buildings that could be fully inspected, 71 percent failed to meet a high threshold of compliance with the city standards, while 36 percent failed to meet even a lower threshold of compliance.

“It would appear that the regulator is not performing its duty,” the study concluded.

But the inspection of older buildings can also be lax, which might have been the case in the tragedy at the Enrique Rebsamen School , where 19 children and 6 adults died this past week following the collapse of one of its buildings.

City code requires that certain buildings, including schools, be inspected for safety after an earthquake. After a massive earthquake hit Mexico on Sept. 7, an inspector was dispatched to the school.

The contracted inspector signed off on the structure, deeming it safe, said Claudia Sheinbaum, the local delegate in charge of the district where the school is located.

“They came to the school to verify the building and said it was O.K.,” she said.

There are still tens of thousands of pending requests across the city for engineers to review structural damages, so the estimate of damaged buildings is likely to grow.