The Missouri Department of Transportation is in an emergency design contract to come up with the new Grand Avenue Bridge.
On May 6, a bridge engineer was driving by and noticed the large crack underneath had grown and several more smaller cracks had developed as well. That engineer called MoDOT Assistant District Engineer Brian Kidwell.
"He goes, 'Hey Brian, you need to get out here. I think we need to close this bridge," Kidwell said.
#Breaking update: Here's a better look at the stress fractures centered around the Grand Ave Bridge closure. #besafe pic.twitter.com/NwFcVwr5LB
— MoDOT Kansas City (@MoDOT_KC) May 6, 2016
Since then, they have dropped the inside lane and added 10 metal studs underneath that hold 30,000 pounds each for support. There are no concerns about the bridge collapsing at this time, nor was that a concern before the closure.
Kidwell added, "Worst case what would have happened is the bottom part of this bridge would have separated from the top and really the bottom half of that bridge would have fallen down onto 670 traffic below."
So what caused it?
"What mainly caused it is this is an old bridge. It's already performed past its designed service life," Kidwell said.
Most of the bridges in the metro were built in the 1950s and 60s, with a life span of 50 years, according to MoDOT. What's concerning is the Grand Avenue Bridge was just rated excellent in September 2015. Several of the more than 60 bridges in the downtown Kansas City area alone are rated worse.
Engineers aren't worried about other bridges failing this way because this is the first time they've seen a sonovoid bridge, one with hollow tubes running the length of it inside, has failed this way.
Chunks of concrete had started falling from the bridge onto 670, a huge hazard for drivers.
"You can actually see the concrete chunks laying on the road. That's what fell out of the bridge," Kidwell told 41 Action News. "I wouldn't want to drive under a piece of falling concrete and I doubt anybody else does."
Once a new design is approved, MoDOT hopes to begin construction as early as August and open it back up to drivers by December with a $5 million price tag.
Kidwell says what's most important is the safety of Kansas City drivers when they're on the road. "This is what keeps MoDOT inspectors up at night," he said.
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Dia Wall can be reached at dia.wall@kshb.com.
