A construction worker was killed at the Gilcrease Expressway expansion site in Tulsa, Okla., on August 16 when a piece of heavy equipment rolled down a steep hill and crushed him.

Noe Mendoza, 45, an employee of Plains Bridge Contracting of Yukon, Okla., was found by emergency responders. Mendoza was hit by a 120,000-lb road spreader, with a big diesel-driven scraper to pick up pavement, and declared dead at the scene, says Bill French, spokesman for the Tulsa Fire Dept.

Tulsa Police Dept. public information officer Leland Ashley said the machine that killed Medoza was a Caterpillar 621G wheel tractor-scraper. The Occupational Safety and Health Administration is investigating the cause, which remains unknown. Darren Bond, Plains Bridge president and owner, says the operator, an employee of United General Contractors, Kingsfisher, Okla., reported that the machine lost power and control when the scraper’s drive pan “wouldn’t go down,” and it rolled about 1,100 feet. Bond adds that team members have met with representatives from Caterpillar, which has two more models in the same series.

In the past decade, OSHA has cited Plains Bridge 19 times for serious violations, including four serious violations associated with a crane accident in 2009.

Plains Bridge and joint-venture partners Treas Construction, Coalgate, Okla., and United General Contractors have a $13-million contract to grade, drain, surface and build two bridges and add signals to 0.7 miles of the expressway.

The city of Tulsa is expanding the roadway to encourage development. The expressway will connect a state highway to Interstate 44, a major route to Oklahoma City. The Oklahoma Dept. of Transportation is overseeing the job, which received federal funds.