NARRATION: Donald Trump has promised to rebuild our nations infrastructure, which according to the American Society of Civil Engineers gets a D+. And lets be honest, we all know thats almost an F.

How did we get to this point?

Because for years updating our crumbling infrastructure has been put on the back burner. Maintaining infrastructure like roads and highways may not seem like a top priority, but it should, because were also talking about bridges. And that can be disastrous.

ARCHIVAL (KSTP, 8-1-07):NEWS REPORT: One of the main iconic bridges in the Twin Cities has collapsed.

ARCHIVAL (KSTP, 8-1-07):HELICOPTER PILOT: The entire bridge is in the water, the 35W bridge is in the water.

NARRATION: At the height of rush hour in August 2007, a major interstate bridge in Minneapolis collapsed, killing 13 and badly injuring many others.

GARRETT EBLING (COLLAPSE SURVIVOR): I broke both my ankles, I broke my left arm, severed the colon, ruptured diaphragm, collapsed lung. My mom said the only way that she could recognize me was by my feet.

NARRATION: The collapse sounded an alarm why had it happened and who was responsible?

ARCHIVAL (CNN, AC360, 8-2-07):ANDERSON COOPER: Its obvious there were troubling safety questions about this bridge years before the collapse.

ARCHIVAL (NBC, 8-5-07):LEE COWAN: Officials are looking at everything, from the weight of construction equipment on the bridge to traffic patterns, vibrations, the weather, even the kind of solvent used to melt the ice and snow in the winter.

NARRATION: The National Transit and Safety Board eventually found that a mistake made 40 years earlier during the bridges construction was to blame. When the state did its own investigation, it faulted insufficient budgets.

TOM JOHNSON (AUTHOR OF REPORT ON BRIDGE COLLAPSE FOR MINNESOTA LEGISLATURE): We came away from our investigation that these are professionals trying to do their job, but they had some very severe restrictions about, you know, what they could do, largely because of lack of money.

NARRATION: These days a growing number of states have stepped up bridge inspections and repairs, but many engineers admit that they are doing little more than triage.

THOMAS JOHNSON: Theres a huge tug towards spending money, politically, where its more visible rather than into something thatthat bridge was standing yesterday, its standing today, why wont it be standing tomorrow?

NARRATION: Over 188-million trips are taken over structurally deficient bridges every day.

LEE PATNER (CONSTRUCTION ATTORNEY, AUTHOR, TOO BIG TO FALL) When we have fracture critical bridges that are structurally deficient, what every engineer knows, they all know, is that that bridge is a ticking time bomb and will fall at some point.

ARCHIVAL (STATE OF THE UNION, 1-30-18):PRESIDENT DONALD TRUMP: I am asking both parties to come together to give us the safe, fast, reliable, and modern infrastructure that our economy needs and our people deserve.

TEXT CARD: It will cost more than a trillion dollars to repair the nations infrastructure. So far, Congress and President Trump have been unable to agree on how to pay for it all.