At 6:05pm on a sweltering August evening in 2007, rush hour traffic was crawling across Minneapolis’ I-35 bridge. Then, the bridge began to shake.

Thirteen people died and 140 more were injured when Minnesota’s third-busiest bridge collapsed, plunging vehicles ten stories down into the rushing Mississippi river and leaving one school bus with 63 children teetering against a guardrail. An NTSB investigation later attributed the collapse to 300 tons of construction materials that had been placed on a 40-year-old design flaw in the bridge’s original construction. But while the flaw had gone undetected for decades, inspectors HAD rated the bridge in poor condition for 17 straight years.

The truth is that bridges in America fall down all the time, Ian Bremmer explains on GZERO World.