Abstract: At approximately 9:30 a.m. on March 19, 2004, Employee #1 was using a Meco Hydraulic Coring Unit (Serial No. PMS1 15-2540, 22957-1), with a Meco 4-in.-diameter, diamond-barrel, hydraulic drive (Model No. M25 H, Serial No. 886), and a Bosch rotary hammer (Model No. 11244E) in a clothes-cleaning establishment. He was drilling a hole through a concrete floor for an environmental sample. The hydraulic concrete corer operated at 1500 to 2000 psi and was approximately 40 in. high. Standard procedure was for employees to secure the concrete corer to the surface by drilling a 0.75-in. hole and using a wedge anchor bolt in the hole to hold the unit. The employee did not secure the corer to the surface. Instead, he leaned over the corer to support it and turned it on. The drilling barrel turned clockwise, and the corer flipped counter-clockwise onto the employee, seriously injuring him. He suffered a bruised chest, laceration to left leg, small cut on right eyelid, and a blow to his head with loss of conscience. Employee #1 was hospitalized for his injuries.