Popular MechanicsHow Much Water Does It Take to Knock Out the Sears Tower?Chicago's iconic skyscraper is in terrifying darkness. Here's what sapped its power.BY CAROLINE DELBERTMAY 20, 2020
TWITTER/LWILZ- Chicago's iconic Sears Tower is in darkness since a flood filled the power vault with four feet of water.
- Floods can knock out power, and utilities often shut off power to flooded areas to make sure people can safely enter.
- The tower is closed until officials can clear it for safe reentry and power, but it was probably pretty empty already.
Chicagoans took to Twitter last night with dramatic photos after the city's iconic Sears Tower—err, Willis Tower—lost power. In these images, the skyscraper looms like Christian Bale's Batman over an unbothered city.
Sᴀʟᴀᴍɪ
@topspittinwraps
Everyone realizing that the sears tower has a face is the only comedic thing that has happened this year
4:19 AM · May 20, 2020
2.8K
573 people are talking about this
Julie Elizabeth
@CubsGirl10
It looks like Gotham tonight. And it’s extra creepy with the Sears Tower totally dark. #Chicago #Skyline
8:58 PM · May 19, 2020
1.8K
393 people are talking about this
But how can the power go out for just one tiny part of the city, and how is the Sears Tower powered in the first place?
Heavy rain gets into the ground and causes electric wiring to, well, go haywire. There are multiple reasons why that can happen. If there are even micro-small flaws in the insulation or connections within a system, water can and will short the system out.
That’s because as soon as conductive water touches the wire, the current is drawn in that direction. When there’s more than one exposed spot, the water can form a circuit—a short circuit.
Over time, repeated exposure to flood waters can cause corrosion and other kinds of damage. And because of the danger to workers and others on the premises, utilities are carefully slow to turn power back on to affected buildings. If every flood represents a new wash of potential damage to the system, every switch-on after a flood involves a new and different amount of risk.
The National Electrical Manufacturers Association recommends all flooded electrical equipment be at least spot checked. In an industry guide to assessing water damage, the organization explains:
“Reductions in integrity of electrical insulation due to moisture, debris lodged in the equipment components, and other factors, can damage electrical equipment by affecting the ability of the equipment to perform its intended function. Damage to electrical equipment can also result from flood waters contaminated with chemicals, sewage, oil, and other debris that will affect the integrity and performance of the equipment.”
This echoes similar water damage fears in everything from used cars (which you can try to sell following a flood, but good luck) to home interiors. And all of it is even worse when the flood is saltwater. Trying to safely and completely dry any of these things is really difficult and often leaves a stench, mold or mildew, corrosion, or some other demerit.
TWITTER/HERRING_NBAIn this case, local news reports: “The power was knocked out at Willis Tower early Monday morning after four feet of water flooded the building's electrical vault. Crews have been working to pump the water out of the building before ComEd can send a team inside to assess the damage.”
As for why the Sears Tower is affected when buildings around it look fine, there are explanations for that, too. The building weighs 440 million pounds and rests all the way down on the Illinois bedrock, with “enough steel to build 50,000 automobiles, and enough telephone wiring to wrap around the world 1.75 times,” PBS explains.
And there’s much more: “Within the building, there are 25 miles of plumbing, 1500 miles of electric wiring, 80 miles of elevator cable, 796 restroom faucets, and more than 145,000 light fixtures,” the official Skydeck website reports.
So a flood that affects the undergirdings of the Sears Tower could happen in any part of a huge area at the base of the building, and the massive amount of materials in the structure opens up a whole bunch of potential “attack surface” for rising waters. In this case, high rise buildings usually have dedicated transformer vaults, and trying to drain four feet of water out of an underground room is a Herculean task unto itself.
With different generations of neighboring buildings built over the nearly five decades since the Sears Tower opened, what affects one doesn’t affect them all. A shorter building with a different electrical structure could just not be affected.
In 2018, the Willis group said the building was at 95 percent occupancy. Few of the building’s tenants would be considered essential businesses, but Willis has closed the building entirely until it’s fully assessed and checked out. “The Chicago Fire Department and Commonwealth Edison (ComEd) have been on site through the night working to assess the situation,” the website says.
Anyone who’s tried to dry out a car or home interior has some idea of the task facing the firefighters and private workers trying to drain and dry this building. Besides sending in a flotilla of DampRid, battery-powered water pumps can pull out a lot and then industrial dehumidifiers can do the rest. After that, ComEd can think about turning the power back on.
