The county has ordered MGM Mirage Inc. to hire an engineer to examine the building to see what actions are needed. MGM has 120 days to submit a report to the county.

"We're going to comply with what they ask us to do," MGM spokesman Gordon Absher said. "We'll do whatever is required to make the building safe."

That might include fixing construction flaws that the company inherited when it bought the Monte Carlo in 2005, Absher said. Aside from the improper resin, investigators found that the exterior coating was thinner than it should be in certain spots and that it didn't encase some foam decorations. However, they said these defects didn't exacerbate the blaze.

None of the problems that were uncovered started the Jan. 26 fire, officials say. Workers using a hand-held torch to cut through corrugated steel caused the metal to melt and ignite foam materials, fire officials reported earlier this year.

Some 120 firefighters fought the blaze, which burned along the roof and spread across the facade of the hotel's upper floors. Water from sprinklers and heavy smoke damaged the rooms.

The fire closed the more than 3,000-room resort for three weeks, and some rooms were taken out of service for renovations. Seventeen people were treated for smoke inhalation or minor injuries.

MGM won't be cited or fined for having materials out of compliance, in part because the company has been cooperative, county spokesman Dan Kulin said.

However, MGM will be asked to reimburse the $18,000 cost of analyzing the materials, said Ron Linn, the county's development services director.

The county paid the initial tab so MGM wouldn't have a hand in the investigation, thus avoiding the appearance of "the fox guarding the henhouse," Linn said.

Because the hotel was built in 1992, it is subject to 1991 codes, Linn said.

A chief concern is the horizontal foam band near the 32nd floor, Linn said, because it contains polyurethane, which spurred the flames.

Pieces of a screen wall on the roof also contain this chemical and also strengthened the fire, Linn said.

Samples were taken from other decorative elements, including those that didn't catch fire, he said. One goal of the testing was to research how various elements reacted to the blaze so that safeguards can be improved.

A foam band on a lower section of the hotel did not burn, Linn said.

County building codes are updated every three years, Linn said. Like many local governments, the county mainly uses the international building codes as guidelines.

MGM will have to ensure its materials, including the resin, meet the manufacturers' standards, Linn said. These standards often take the place of codes simply because governments can't keep up with all the new products coming out, he said.

"There are more things out there than the codes can cover," Linn said.

Contact reporter Scott Wyland at swyland@reviewjournal.com or 702-455-4519.