Abstract: At approximately 9:53 a.m. On December 1, 2010 Employee #1 was seriously injured at the employer's jobsite located on Highway 50W between Jefferson Blvd. & Harbor Blvd. The Employer is a general engineering contractor. The two employees involved were working in the center divider splicing low voltage traffic loops. The employees had closed the shoulder according to CalTrans specifications prior to starting work and had positioned their vehicles in front of the work area as a safety precaution. Employee #1 was leaned over working on the k-rail when he heard a loud crash and looked up. The errant driver struck the work-truck approximately 15-20 ft. in front of the workers causing it to crash into Employee #1 pinning him between the truck and the k-rail. According to CHP and CalTrans, the driver had been reported to CHP as driving erratically just prior to the accident. It was later determined that the driver had suffered a heart attack while driving. Employee #1 was a Journey level electrician and had been properly trained in traffic control and was in fact training an apprentice that day. According to the owner, Employees had been issued new vests meeting the new ANSI standard 107-2004. However, the vest that was being worn by employee #1 that day was an older vest, not meeting the new ANSI standard. Employee #1 stated he had several vests in the truck and had not been particular about choosing one that day. Although, he couldn't specifically remember he did confirm that the vest he was wearing was on the outside of his jacket and it was possible it was an older vest. Employee #2 was wearing the correct vest.