On my commute home from St. Paul to the western suburbs of the Twin Cities, a little before 6 p.m. on August 1 last year, I neared the 40-year-old I-35W bridge. Construction work had blocked half the lanes and choked it with traffic, so I passed by and took a different bridge over the Mississippi. Fifteen minutes later a truss-supported section near the southern end of I-35W failed, causing a chain reaction that brought down 1,200 linear feet of bridge and sent 100 vehicles crashing into the river. Thirteen people died.

Never had I been so near an unnatural disaster in the offing, although I have studied the business of techno-catastrophe in depth. Over the past two decades as a journalist, I have analyzed space shuttle breakups, capsized oil rigs off Newfoundland and Brazil, a rocket-fuel-factory explosion in Nevada, and nuclear mishaps in Idaho and Pennsylvania. But of them all, this event particularly troubled me—and not just because it occurred in my backyard.

Shortly after the collapse, a CNN producer called. “Which ridges in the United States are unsafe to drive across?” he asked. Many bridges certainly needed repairs, I replied, but I could not identify specific ones to avoid. That question prompted me to pose one of my own: “How is a society that craves a high standard of living going to take care of a high-maintenance infrastructure while hitting its credit limits?”

A new I-35W bridge is going up now, paid for by federal emergency money. But the mood is not happy at the state capitol where politicians argue about whom or what to blame. Citing Mark Rosenker, chair of The National Transportation Safety Board, who inferred that bad design, not lack of maintenance, played a significant role in the collapse, anti-tax proponents insist that bridges and highways receive ample funding from bonds and gas taxes already.

Pro-tax advocates argue that penny-pinching neglect played a part in the structural failure. In the end, the legislature removed the incumbent transportation commissioner and hiked the gas tax, overriding a gubernatorial veto. While recriminations will likely continue over home much those responsible knew and when they knew it, the disagreement ultimately centers on how much we should spend on repairing and maintaining old bridges and highways.

The proliferation of heavy trucks sits on my short list of culprits for shortening the lives of I-35W and other older bridges built before the major structural improvements in steel bridge construction in the 1970s. Since then, not only has semi-trailer traffic nationwide more than doubled, but the legal limit for each rig has risen from 72,000 to 80,000 pounds. Spot checks by Nevada troopers in 2006 found that one in 14 trucks weighed over the legal limit. These extra pounds add up to major wear and tear on the nation’s roads and bridges.

Whatever the reason for its collapse, I-35W joins a growing list of other North American highway spans with the dubious distinction of killing people recently, including Silver Bridge in West Virginia, Mianus River Bridge in Connecticut, Schoharie Creek Bridge on the New York State Throughway, Hatchie River Bridge in Tennessee, and Autoroute 19 Bridge in Laval, Quebec.

The Minneapolis bridge failure forces us to think about the “industrial web,” the worldwide network that provides the food, fuel, and hardware of daily life. We prefer to take the industrial web for granted, even though it is the crowning achievement of our time, just as Beauvais Cathedral was for the French Catholic Church in the 13th century. It supports a lifestyle of ease and comfort that hundreds of millions hold dear and billions more are seeking. We notice the web only when it is interrupted. In 1995, for instance, an earthquake damaged the container port in Kobe, Japan, sending shock waves through the global auto-assembly supply chain. More recently, a minor short circuit in Florida shut off power to 4 million people.

We are entering what I call the “Third Great Industrial Revolution,” which promises to be even more dramatic than the previous two. Experimenters and artisans dominated the “Age of Invention,” which lasted into the late 1800s. Design and construction of equipment from steam engines to muskets followed rules derived from trial and error. Some gear held up well, and still runs today. Technology that did not bear up included dozens of under built, overused railroad bridges that collapsed during the 1880s.

Next came the “Age of Mass Production,” marked by large-scale consumption of products and the erection of dams, canals, power grids, airports, communication networks, railways, and roads. Designers built in safety margins so that these large civic projects could handle two or three times the expected load. The last epic public works project in the United States was the interstate highway and bridge system.

America stands on the bring of a third revolution, which I call “The Age of Holding It All Together.” The word heralding the era is “infrastructure.” Even before the I-35W bridge collapse, the American Society of Civil Engineers reported that $1.6 trillion was needed within five years to fix up aging sewage plants, highways, bridges, water supplies, locks, dams, levees, and more. So it seems that 21st-century Americans have been handed a box of rusty bolts. Our job is to maintain the industrial web in the face of increasing stresses.

Technology thinkers sometimes refer to the perils of a “no-slack system,” a collection of machines stripped of safety margins and emergency reserves. Major highways in Minneapolis, for instance, are carrying so much extra traffic from the I-35W detour that rush hour now feels like a no-slack system. After the transportation department shifted the stripes to squeeze an extra lane into the concrete-walled trough that is Interstate 94, we commuters have honed our skill and nerve, taking each curve and dip with the steely focus of Formula One drivers.

Pennsylvania miners called the deliberate removal of the safety margins “shaving the pillar,” in reference to cutting coal from roof-supporting pillars and selling it. Last year, a similar technique called “retreat mining” went bad and killed six workers at the Crandall canyon Mine in Utah, followed by the deaths of three would-be rescuers.

Hundreds of other safety margins and reserves are being shaved currently: oil refining capacity that cannot keep up with rapidly rising world demand; overloaded power lines in Connecticut; nuclear power plants with acid-corroded pressure vessels; farmers running out of water for their crops; emergency rooms backed up for hours; flawed dams (including the one in Iraq that pus half a million people at risk); and major airports so congested that collisions on runways and taxiways now pose a greater risk to travelers than in-flight hazards.

There are solutions. World War II wiped out thousands of bridges, but war-ravaged nations somehow rebuilt those with U.S. help, so we should be able to repair the deteriorating bridges of our time. We should stop building new highways until we have gotten control over the crumbly ones. New bridges must be better able to tolerate such things as neglect and overweight trucks—and take advantage of smart-bridge technology. The new I-35W bridge will feature sensors that war engineers about cracks and warps or impending failure.

Engineers believe the new bridge will stand for a full century, a claim that may seem wildly optimistic, but stone and steel bridges can last even longer if well built and maintained. The steel-alloy Eads Bridge in St. Louis still carries commuter trains and vehicles across the Mississippi after 134 years of service. Visitors to the Tajo River Valley at Cáceres, Spain, can read this epitaph on a monument overlooking a stone bridge: “I, Gaius Julius Lacer, famed for my divine art, leave this bridge for eternity and all the centuries of the world.” Or a good start on eternity, at any rate: Lacer wrote those words 1,900 years ago. Despite suffering serious wartime damage on two occasions, Lacer’s nearly 200-feet-tall bridge remains in use, carrying cars, busses, and trucks each day.

Our industrial web could use more builders such as Eads and Lacer, who gave the world technological innovations that did not break down.