The Hoover Dam Bypass project was supposed to be wrapping up about this time.
But in September 2006, a crane collapse delayed construction of the $240 million concrete arch bridge project by nearly a year and a half.
The cause, apparently, was an act of God, with 55 mph winds blamed for knocking over the pulley-type "high-line" crane system.
Or so we were told.
For the past few months, I have been trying to find out from federal officials what really caused the collapse, with little success.
My efforts came after Dave Zanetell, the federal project manager of the bypass, left me a voice mail awhile back.
"The Federal Highway Administration ... we did an investigation related to the environmental factors at the time of the event, in other words to assess if it was an act of God, such as a giant flood or a tornado or something such as that, which changes contractual provisions, and it was not an unusually severe weather or environmental factors at the time as we stated previous," he said.
I sent a Freedom of Information Act request asking for access to findings into the federal investigation into the collapse.
Federal Highway Administration division engineer Ricardo Suarez wrote me a letter stating, "We do not have any documents which are responsive to your request."
He did not elaborate about what happened to the crane system.
Apparently if there was a federal investigation into the crane collapse, nobody wrote anything down.
I also have been told there was an investigation into the collapse that was handled by the primary contractors of the bypass, a multinational conglomerate made up of Obayashi Corp. and PSM Construction USA Inc., but apparently that internal investigation isn't open to public scrutiny. It should be noted that the contractors had to absorb the cost of rebuilding the crane system.
Unfortunately, since his voice mail, I have tried to speak with Zanetell on several occasions, but we've missed each other's calls.
So at this time we still don't know exactly what caused the cranes to collapse back in 2006.
But in the wake of last week's death of 48-year-old construction worker Sherman Jones at the bypass construction site, what happened with those cranes in 2006 has been nagging me.
Federal officials said Jones' death was an accident that happened during a routine operation to adjust a cable used to align the temporary concrete towers that support construction of the bridge's arches. The U.S. Department of Labor's Occupational Safety and Health Administration is investigating the incident.
I don't know why Federal Highway Administration officials don't want to talk about what caused the crane system to collapse.
I do know when the bypass is completed, more than 17,000 cars and trucks are expected to use the new bridge on a daily basis, a number expected to grow by 50 percent over the next 20 years.
And I think those motorists deserve a little transparency about what happened that September.
When it is completed, the bypass bridge will span Black Canyon above the Colorado River and cast its shadow over the Hoover Dam, one of the great engineering marvels of the 20th century.
By not being forthright about what happened to those cranes, the Federal Highway Administration is taking the chance of casting a shadow of doubt over the integrity of the iconic Hoover Dam Bypass project.