This was due in part to outdated construction practices.
And many people were already raising questions about whether slipshod construction practices had made a bad situation worse.
He called for changes in construction practices in the city.
Many critics say the construction practices significantly added to the storm's damage toll.
Agencies managing big public works could keep closer tabs on construction practices.
The accident was later attributed to improper design and poor construction practices.
The remaining 20 percent results from poor construction practices.
"It is standard construction practice for there to be substantial connections between the floors and the wall," he said.
When these construction practices were tested in the laboratory after the earthquake, he said, they failed.
In addition, many are moved physically in soil through construction practices.
