St. Paul Mayor Melvin Carter ordered the shutdown of a major downtown parking ramp Thursday, the day after a chunk of concrete fell on a parked car and two days after he and other local leaders launched a public campaign for $58 million in state money to replace the aging structure.

No one was injured when a slab of concrete measuring 3 feet by 2 feet peeled off the ceiling of the 1,600-stall RiverCentre parking ramp Wednesday night. But the timing could hardly have been more fortuitous, as city officials joined business and union leaders in mounting a public campaign for spending $116 million to replace what they called a crucial facility for downtown.

"This incident underscores the critical condition the ramp is in, and the urgency with which we need to build a new ramp to serve the 2.1 million visitors it serves each year," Carter said in a statement.

In an interview before the mishap, Carter acknowledged that a new RiverCentre ramp is not the easiest sell.

"We're talking about a parking ramp, and one of the challenges of talking about a parking ramp is it's not going to be the most exciting conversation at the Capitol," he said. "But again, this is the piece of critical infrastructure that makes so many things work downtown and for our state."

The city planned to match the state bonding dollars to cover the full cost, but the $58 million was not included in the bonding bill passed by the House.

The Senate version, which included $5 million to demolish the ramp, did not pass.

Built in 1970, the RiverCentre ramp is perched on a bluff across Kellogg Boulevard from the RiverCentre and Xcel Energy Center, the major entertainment venues in the city and home of the Wild.

In 2015, city engineers found structural deficiencies, as well as issues associated with the ramp's design — it doesn't have sloped floors for drainage, among other problems, and most of its mechanical, electrical and operational systems are original or in poor condition. They recommended demolishing the ramp and building a new one by 2020.

In the past 18 years, St. Paul has spent more than $15 million on ramp maintenance and repairs. More recently, an outside engineering firm has conducted monthly repairs and inspections, and removed loose concrete as needed, said Ricardo Cervantes, director of the city's Department of Safety & Inspections.

On Wednesday evening, crowds flocked downtown to see Hall & Oates play at the Xcel Energy Center. According to Cervantes, it was during the concert that RiverCentre ramp staff noticed a piece of concrete was hanging from the ceiling over a parked car. They removed it and cordoned off the area, he said.

After meetings and a visit to the ramp Thursday morning with engineers and a city building official, Cervantes said, they decided to close the ramp to allow for a more comprehensive inspection.

That inspection will begin Friday, Cervantes said. It's unclear when the ramp will reopen, leaving downtown visitors and people who park in the ramp on weekdays in limbo.

"This is going to be a major blow to vibrancy until we can find a way to re-establish where those parking spots are going to be," said Council Member Rebecca Noecker, whose ward includes downtown.

As of Thursday afternoon, the RiverCentre website had been updated to announce the ramp closure and direct visitors to other downtown parking ramps, as well as to alternative options including transit and bicycling.

In the meantime, St. Paul leaders are continuing to tout the ramp's importance in the downtown entertainment district in hopes of securing last-minute legislative support. The new ramp would have 2,200 spaces.

"This bonding request is truly needed for this parking ramp that is utilized for people all around the state of Minnesota, from all around the country," said Rep. Rena Moran, DFL-St. Paul, in an interview Thursday.

With the session scheduled to end in days, Moran said the RiverCentre ramp remains her top priority.

"I am not giving up," she said.

Emma Nelson • 612-673-4509