Abstract: At 11:30 a.m. on March 4, 2019, Employee #1 and a coworker, employed by a concrete construction company, were building a 4-foot tall retaining wall. They were stacking limestone and cement blocks measuring 46 inches by 18 inches by 7 inches to build the wall. The coworker was operating an XCMG XE210 crawler excavator with a bucket holding chain slings connected to wire rope, used to lift, transport, and place each block. Employee #1 was standing under the excavator bucket with his left arm on a block that had just been placed. He had removed the wire rope and was preparing to mark and trim the block when the excavator bucket fell onto his arm. His arm was crushed between the bucket and the block. Emergency services transported Employee #1 to the hospital, where he was admitted for treatment of his crushed left arm.