That's because Nevada has some of the nation's strictest laws governing crane operations, said Steve Holloway, executive vice president of the local chapter of Associated General Contractors.

Credit the stringent regulations to the aftermath of a 1994 tower-crane collapse in Laughlin. The accident killed three people in a hotel-casino parking lot, and it encouraged area construction trade groups, unions, state legislators and officials of the Nevada Occupational Safety and Health Administration to step up requirements on the assembling, operating and dismantling of cranes.

Among other measures, the laws that followed the Laughlin collapse call for clear zones when builders assemble or dismantle cranes, or conduct "highly hazardous lifts." They also demand annual certification of cranes' mechanical lifting parts, plus certification each time a tower crane is erected.

Fifteen days before a builder puts up a tower crane, the company must notify Nevada OSHA, bring in building plans and meet with OSHA officials. The same process covers crane dismantling. All crane operators must undergo extensive training, pass "pretty difficult tests" and earn state certification, Holloway said.

It took more than a year to craft the rules in the mid-1990s, and they're still undergoing refinements: Even operators of smaller cranes that handle tasks such as placing residential air-conditioning units outside homes must now be certified to run the equipment.

Rigorous regulation of tower cranes in particular is important because maneuvering the machines calls on substantial technical skills, Holloway said.

"Most of these accidents happen because someone did something wrong," he said. "When you're operating a crane like that, you have to make some fairly extensive math calculations. You have to know algebra. They have computers in the cab on most cranes that help operators do those calculations, but it's a pretty technically oriented job."

Managers at two of the city's biggest crane dealers, Dielco Crane Service and Jake's Crane & Rigging, didn't return calls seeking comment by press time.

Tom Czehowski, chief administrative officer of Nevada OSHA, declined to comment on how safe Nevada's tower cranes are. He also wouldn't discuss whether crane-operating laws in the Silver State are stricter than regulations in other states. He didn't have statistics on crane-related accidents or fatalities on Nevada construction sites.

The Las Vegas area has witnessed at least one high-profile tower-crane accident in recent years, though.

High winds crumpled four tower cranes in September 2006 at the construction site of the Hoover Dam bypass bridge project, on the Arizona side of Black Canyon. No one was hurt in the equipment breakdown, but the crane collapse did shut down U.S. Highway 93 and the Hoover Dam visitor center for four days.

Contact reporter Jennifer Robison at jrobison@reviewjournal.com or 702-380-4512.