Edward Lake, Jr., 60, was struck as he was unloading rebar at the stadium construction site at about 6:45 a.m. He later died from his injuries at the hospital.
The incident is under investigation by Cal/OSHA, Santa Clara Police and the Santa Clara Fire Department.
State officials have investigated the incident and determined the construction site is safe. It will re-open Tuesday.
The San Francisco 49ers have released this statement: "The 49ers organization learned this morning that an accident occurred involving a driver as he delivered materials to the stadium. Our sincerest thoughts and prayers are with the family, friends and co-workers affected by this tragedy."
Gerdau said it was, "Saddened that an employee passed away after a serious incident this morning at the Levi's Stadium construction site."
This is the second fatal accident this year at the construction site. In June, a worker died while working on the stadium. Don White, 63, was on the ground floor of an elevator shaft on the east side of the stadium when the accident occurred. According to Cal/OSHA, White was standing on a ladder beneath the elevator counterweight when the counterweight struck him. White was a father of four and grandfather to three.
Levi's Stadium is scheduled to open next year for the start of the 2014 season at an estimated cost of more than $1.2 billion. The nearly two million square foot stadium will have 68,500 seats. The stadium is set to host Super Bowl 50 in 2016.
With the job site declared safe, workers will return to the job Tuesday morning. Employees will also be offered on-site counseling to deal with the death of a coworker.
Edward Lake, Jr. lived in Vacaville
One of Lake's Vacaville neighbors described him as a very nice person who liked to keep to himself. Lake's father was a professional baseball player. He was an infielder with the Detroit Tigers, Boston Red Sox and St. Louis Cardinals in the 1940s.
Gerdau has a safety sign posted that warns drivers to be in their trucks or far away when loading or unloading rebar.