An employee was working at a customer's address to troubleshoot an in-channel frequency response issue. The employee was preparing to check radio frequency levels at the tap located on the strand next to a wood utility pole at the end of the customer's concrete pad driveway. He set up his 28-foot extension ladder onto the wood utility pole and began his ascent. He ascended the ladder to about the 13th or 14th rung and was reaching for his fall restraint lanyard to secure himself and the ladder to the pole when the pole began to break at its base. He fell from the extension ladder from a height of approximately 13 or 14 feet and contacted the concrete pad driveway below, landing on the side of his body and suffering fractured ribs.