A stormy Sunday afternoon in Dallas with gusts of 70 mph or higher. A tower crane tied to a new apartment building frame tumbles, smashing a completed parking structure behind it.

When securing a jobsite against malicious hackers, most go to protect computer files, and few look up and worry about the tower cranes.

A tower crane being dismantled collapsed Saturday, April 27 in Seattle, killing two ironworkers on the crane and two bystanders on the street below.