MINNEAPOLIS (WCCO) — We’re following the latest developments Friday morning on a story that touches very close to home for Minnesotans.

A portion of a bridge on a busy interstate in Washington state collapsed Thursday, sending two cars into the water below. It happened about an hour north of Seattle on Interstate 5.

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Investigators are working to try to figure out what caused a portion of the four-lane bridge on the Skagit River to suddenly give way. It all started around 7 p.m. Thursday as a portion of the bridge dropped 50 feet into the water. A car and a truck pulling a trailer were on that section of the bridge as it collapsed and ended up in the water.

Authorities said the three people inside those vehicles were taken to the hospital with non-life threatening injuries.

The bridge was built in 1955 and state officials said it had passed every inspection/ It had two done just last year. Federal records show it has a sufficiency rating of about 57 out of 100 and is listed at “functionally obsolete,” but it’s also noted in the report that the bridge was adequate enough to be left in place.

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“It’s the aorta of transportation, commerce and industry in western Washington, and we have already started the process of designing a system of detours to accommodate the time period it will take to replace this bridge,” said Seattle Gov. Jay Inslee.

One of the people who was rescued said he saw a semi-truck in front of him hit the bridge right before it collapsed. Investigators are still trying to determine if that was in fact the cause.

Interstate 5 is a highly-traveled section of highway that connects Canada to Seattle and the rest of the west coast. It will have a big impact on traffic in the area for a while as it’s closed for repairs.

Of course the even hits too close to home for Minnesotans. It’s been nearly six years now since the Interstate 35W bridge collapsed into the Mississippi River in downtown Minneapolis. It was a day where 13 people died and 145 others were hurt.

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The collapse happened during the height of the evening rush hour, on Aug. 1, 2007. Engineers said undersized gusset plates and too much weight on the bridge caused the collapse.

Kate Raddatz