DENVER -- The company that maintains the malfunctioning Coors Field escalator that injured 35 people earlier this month lashed out at city inspectors Wednesday, saying their investigation is "irrelevant" and could damage the machine.

Kone Inc., whose U.S. operations are based in Moline, Ill., holds the maintenance contract for all seven escalators at the downtown ballpark.

The city plans to load the escalator with weights Thursday to simulate crowds that rode it July 2, when it suddenly sped up. Fans headed home from a Colorado Rockies game and fireworks show were dumped to the bottom, many of them suffering broken bones and severe cuts.

City inspectors say they want to determine whether the escalator brakes could hold such a load. A preliminary investigation has suggested that improper brake settings or overloading contributed to the accident.

However, Kone chief executive Trevor Nink said the simulation would only further damage the escalator.

"It is the equivalent of testing a car after it's been through an accident but before it's been repaired. A damaged vehicle obviously won't perform the way it would in good working order previous to the accident," Nink said in a statement.

Kone Inc. said it prefers to let experts and engineers use diagnostic tests to figure out what went wrong. It also said the investigation has been slowed by the expectation of lawsuits from victims.

"It's taken us awhile to get to this point because it's a complex issue and because there's a threat of litigation sitting, so it isn't just flowing naturally," said Bill Zucker, spokeman for Kone Inc. " But we now think we have the appropriate tests to bring this to some conclusion."

Private escalator consultant Steve Greene of Petaluma, Calif., agreed the simulation might be difficult because it could damage the escalator. He said the test weights would crash into the comb plate at the bottom of the three-story device.

Greene nevertheless said the idea was worth exploring for testing manufacturers' recommended brake settings.

"We don't have any other way to check it than loading the steps full of weights," he said. "That's never been done. We've always taken for granted that the design of the brake is sufficient."

City inspection procedures have been under scrutiny since the accident. The Community Planning and Development agency, which inspects the escalators, relies on manufacturers in many cases to inspect the machines and file reports on their condition.

The agency has said Kone has never filed annual inspection reports for the escalator since Coors Field opened in 1995. Nink said the city never asked for them.

Kone is preparing to send those reports, agency spokesman Julius Zsako said. The city also requested Kone's reports for escalators at the Pepsi Center, he said.

In the meantime, all escalators at Coors Field will remain closed through this weekend's Rockies homestand.