9/11 nearly caused an infrastructure disaster: The little-known story of the wall that held

Tens of thousands of volunteers and first responders spent months in the rubble in the aftermath of the Sept. 11 terrorist attacks in Lower Manhattan.

First, a search and rescue. Then, a recovery.

The focus was above ground. So was, understandably, the news coverage.

But Peter Rinaldi was below ground, and his team had its own search mission for a wall beneath the World Trade Center.

And if it collapsed, when the towers did?

“It would have been catastrophic,” said Rinaldi, an engineer with the Port Authority of New York and New Jersey who worked extensively on the site after 9/11.

Read more at NY1