Two employees were erecting a hydraulic mast climber scaffold with an eight-foot extension work platform. They erected it to the maximum height of 30 feet and were lowering the scaffold to install ties. While lowering the scaffold, there was a malfunction and one of the sides of the scaffold did not catch, causing it to come down quickly. A safety mechanism caused it to catch, but the force caused the other tower to tip over. The employees were ejected from the platform but were tied off to the guardrails/hoists above them using self-retracting lanyards. Employee 1 was hospitalized with bruises, lacerations, and a concussion. Employee 2 was hospitalized with bruising, facial lacerations, and a shoulder injury.