Closures near the foot of Canal Street are unearthing a problem many residents didn’t even know existed.

It’s a 50-year-old problem in the making.

Underneath the street, a tunnel which stretches from Canal to Poydras Street is starting to buckle and has caused a shut down in the area.

The tunnel was built by the city in 1966 as part of a planned Riverfront Expressway that would have run along the edge of the French Quarter.

“It was probably a temporary design made out of steel and they probably didn't paint it," says engineer H.J. Bosworth. "Those unpainted structures under the City of New Orleans don't stand a chance."

Bosworth said the concern now is if the damage underneath will cause the street above ground to collapse. He said there are several layers of concrete that prevent major damage.

"The collapse wouldn't be catastrophic and things dropping like 20 feet or anything like that,” Bosworth explained. “Something like that collapses little by little."

The plans for the tunnel were cancelled in 1969 and since then parts of it have been used for parking at Harrah's Casino.

On Friday one of the walls became a concern for city officials when it reportedly began to bulge and started leaking water.

Drivers who tackled this for the first time said they had no clue Canal Street wasn't the issue.

"This is not very thought out," one motorist said.

When WWL-TV told another driver there was a tunnel underneath he simply replied, "Man that is nuts."

"Safety is the No. 1 priority in this situation,” Department of Public Works Director Mark Jernigan told our media partners at the New Orleans Advocate.

The U.S. Army Corps of Engineers said that the presence of water in the tunnel is not an indication of problems with a floodwall in that area.

The city said in a written statement they are working to access the damage and additional street closures could happen if the problem gets worse.