Six people died yesterday in Philadelphia when a 4 story building being demolished collapsed on the adjacent Salvation Army Thrift Store.

“You felt it shake,” Jordan McLaughlin told CNN affiliate KYW. “There was people that actually fell over. People started screaming, they ran across the street. There was people inside the building, you heard them scream.”

He said he helped two people out of the building. Other bystanders, including construction workers, helped four or five others out in the moments after the collapse.

This first photo from Google Maps shows the street view before the building collapse.

While the next photo shows the rubble. Imagine shopping in that Thrift Store at the time of the collapse?

The crews demolishing the 4 story building certainly felt they were proceeding in a safe manner. But then the unexpected happened.

The day before, I got called to look at a wood frame renovation project we’re doing, because the structure wasn’t normal. As we stood there looking at what we saw vs what we had assumed, I kept asking the opinion of Andy Hess, the project superintendent. Andy looks like a big old biker (which he is), but knows more about how wood structures actually work than I ever will. His practical knowledge trumps my theoretical knowledge.

I’m glad I learned, early in my career, to ask lots of questions of the folks doing the work and to listen intently and respectfully to their answers. They don’t always say it in the clearest manner, but the best insights and solutions often come from these guys.

Arrogance on the jobsite is always the wrong approach.