The Angels are in the Details: Utilities, Our Unsung Heroes

Last week I visited to the 9/11 Memorial and Museum. It was my first visit there since 2001, and my wife and I took the museum tour. It was astounding to experience the same emotions again from that day - two of the exhibits capture statements, written and verbal, from people who remember where they were when the Twin Towers were attacked and when they fell. I was in my in-laws' living room, having been at the Word Trade Center subway stop the day before for an interview. I still remember the shock and horror of that time.

I am grateful that I took the museum tour for a number of reasons, not the least of which is the ability of the tour guide to orient you to the artifacts and stories of both survivors and those who lost their lives.

Two parts of the tour, however, really stood out to me.

The first was a reminder that the World Trade Center (WTC) had been bombed in 1993, and according to a study after that attack, the median evacuation time for occupants was 1 hour for Tower 1 and 30 min to an hour for Tower 2. Following the attack, the WTC put in place signage, training, and fire drills. On 9/11 it is estimated that 10,000-14,000 people were in the Twin Towers that morning, and 99 percent of people below the impact points were able to escape.

The second is a section of the slurry wall - holding back groundwater from the Hudson River - that continued to stand following the collapse of the tower. Had the slurry wall collapsed, the foundation, connected PATH tubes, and the subway tunnels would all have been submerged with water.

For the most part, the people who studied the WTC after the 1993 attacks and instituted emergency procedures or designed and built the slurry wall are unknown. (The New York Times ran an