Minnesota playground equipment manufacturer Xccent Inc. anticipated a big day for its company two years ago when it showcased fanciful climbing structures, bridges and slides in the Minneapolis Convention Center.

"Imagine a girl in high school planning for senior prom four years in advance," said Xccent owner John Mathiesen, whose company relocated from Wisconsin to Wyoming, Minn., in 2010, hoping to make a splash at the annual congress and expo of the National Recreation and Park Association (NRPA).

Then it started raining -- indoors.

More precisely, to quote Xccent's recent lawsuit against the city of Minneapolis, "rainwater leaked through the roof of the convention center to such an extent that it was literally raining in Xccent's booth." The big day was essentially ruined, the company claims.

In court filings, the city admitted that the booth probably got wet, but it wasn't enough water to be a washout.

The convention center's leaky, 23-year-old copper domes are currently undergoing a $4 million to $5 million plastic-shell upgrade to seal convention-goers from the elements. The city has invested more on short-term fixes in the past five years, but convention center executive director Jeff Johnson hopes the new roof will be complete by Oct. 31.

Star Tribune
Workers put a new plastic shell on the Convention Center domes to stop water from leaking into the building.

The overhaul follows another incident in March when gunk from the roof dripped onto a car at an auto show. But it comes too late for Xccent, which sued the city earlier this year after failing to get a refund for its rain-soaked booth.

What Xccent had arranged beneath the roof was not a mere jungle gym. In its 2,500-square-foot exhibit space, one of the structures, known as Triax, featured converging blue bridges attached to various slides, ladders and climbing poles.

The city was prepared for leaks when they began, unfurling a parachute-like device with an attached garden hose to catch water. Still, Mathiesen said, the rain soaked the carpet, dripped on the equipment, marred catalogs, and caused one woman to slip. At the start of the 2 1/2-day conference in October 2010, they could conduct business only in the aisle.

The company had just expanded its product line by about 60 percent and moved into a new factory in Wyoming after receiving state incentives. Officials hoped that trumpeting the company's assets at the convention would lure new distributors, who like to get up close to examine paint, welds and other details.

"How many distributors wouldn't even come talking [to] us because of the situation?" Mathiesen said. "We couldn't even measure."

Mathiesen said the total cost for attending the convention amounted to about $183,000, including $61,000 to rent the booth. The suit seeks damages "in an amount far in excess of $50,000," a standard clause in civil complaints.

The city admitted in a legal filing that water leaked through the roof, but "denies that during a rainfall of even a modest amount, a significant amount of water would drip onto areas that it leased" to the NRPA.

The city added that it only has a contract with NRPA -- not Xccent -- for use of the space, so it had sued the wrong party.

"Plaintiff's injuries and damages, if any, were caused, contributed to, or worsened by Plaintiff's unlawful, unreasonable or illegal acts," the city's filing said.

City officials did not return messages seeking comment. An NRPA representative declined to comment. Mathiesen said they're just trying to do "the right thing."

"We weren't treated properly and we're going to hold them accountable," Mathiesen said.

Eric Roper • 612-673-1732 Twitter: @StribRoper