The crane crushed Arnett at about 9:30 a.m. Wednesday at Berth 37 of the port, Cal-OSHA spokesman Peter Melton said.
Arnett, who worked for Ports America, which is based in Jersey City, N.J., suffered a crushed chest and head injuries, Melton said. Arnett was transported to a hospital where he was pronounced dead, according to Melton.
Melton said the fatal accident was caused by some type of maintenance issue when Arnett and another worker were working on a crane trolley, a large piece of equipment with four wheels that rides on rails and moves cargo to ships for transport.
He said maintenance work needs to be performed on the trolley periodically because the wheels get off center.
Melton said Arnett and the other worker were trying to adjust the trolley but when the trolley moved forward Arnett was pinned between the bumper of the trolley and a guardrail.
The company that owns the crane, Evergreen Marine Corp. of Taiwan, agreed not to operate the crane until the maintenance work is completed, Melton said.
When that work is finished, Cal-OSHA will inspect it sign off on it before allowing the crane trolley to be put back to work, he said.
Berth 37 is one of seven terminals at the Port of Oakland and was shut down for the day on Wednesday after the accident. But Port spokeswoman Marilyn Sandifur said the terminal re-opened Thursday.
Sandifur said Port employees worked collaboratively with Arnett from time to time and described him as "a very-well liked man."
In a statement, Ports America said it is "extremely saddened by this tragedy."
The company said, "We extend are deepest sympathy to his family. The safety of our employees is of the utmost importance to us."
Melton said Cal-OSHA's investigation into the accident will look at whether Arnett and the other worker were properly trained. He said Cal-OSHA will interview other employees at the port and look at maintenance records for the crane.