Missouri state officials are not yet sure when the westbound lanes of the Jefferson Barracks Bridge will reopen to traffic after inspectors found a massive 6-foot crack in the bridge last weekend.

All westbound lanes on Interstate 255 on the bridge crossing from Illinois to Missouri have been closed since Sunday after the massive crack was found during a routine inspection. The bridge was last inspected two years ago.

In the days since that major crack was found, other cracks have also been identified on the bridge.

The damage is so severe that the the Missouri Department of Transportation is now mentioning the possibility of constructing a crossover bridge to switch westbound lanes onto the eastbound bridge while repair work goes on, but that will depend on “very extensive” inspection test results that are now expected late afternoon Thursday.

MoDOT originally thought a solution and timeline for repairs might be announced as soon as Wednesday as days of inspection finished up, but the agency is now saying answers won’t come until tomorrow.

Once MoDOT receives the results from the lab report Thursday, the agency will decide if it can reopen the bridge, or if it will have to build a cross-over to move westbound I-255 to the eastbound bridge.

The agency will not reopen the bridge until it can verify that it is safe, it said in an update posted to its website.

Inspection crews working underneath the bridge, including a specialist flown in from Seattle, are nearing completion of their more in-depth evaluation of the bridge over the Mississippi River.

The department is awarding an emergency contract to get additional resources on the bridge to complete needed repairs, and has already started making repairs. Personnel and equipment from both MoDOT and the Illinois Department of Transportation as well as two private companies are working on the bridge.

“We don’t take making the decision to close the bridge lightly, but safety must be our primary concern in cases such as this. We are doing everything we can to expedite this process, and are working around the clock to reopen the bridge as soon as possible after we can definitely verify the bridge is safe,” said Tom Blair, district engineer for MoDOT St. Louis.

Inspectors found the 6-foot crack under the weld of a critical portion of the bridge’s structure. Further inspections have found similar cracks in other similar locations of the westbound bridge, but none of them are as severe as the initial crack found Sunday.

MoDOT said in a news release that it continues to coordinate with various partners, including IDOT, emergency responders and local construction teams to mitigate the situation, determine a repair and “get the bridge open to traffic as soon as safely possible.”

The JB Bridge was finished in 1985, and about 60,000 cars travel the eastbound and westbound lanes of the bridge daily.

Several crashes around the region resulted in extensive backups during Wednesday morning’s rush hour.

During the closure, MoDOT recommends that commuters consider getting onto the interstate system as soon as possible and use all Mississippi River crossings between Illinois and Missouri, or, if possible, using MetroLink, shifting their commute times, or telecommuting. IDOT has also increased staff on hand to update signs and adjust signal timing.

Commuters from Illinois are primarily taking an alternate route to South County through downtown St. Louis at the Poplar Street Bridge and Illinois Route 3.

The MLK Bridge is currently shut down for a year for refurbishing.

But the newer Stan Musial Veterans Memorial Bridge saw only a slight increase in traffic Monday morning, and there was no change in traffic on the westbound Chain of Rocks Bridge.