This paper discusses the effects of Hurricane Maria on Puerto Rico's electric grid. Arguably, the most significant effect of Hurricane Maria on Puerto Rico was the electric power outage that initially affected the entire island and lasted more than ten months. Although the damage to the conventional electric power generation infrastructure was relatively minor, both the transmission and distribution portions of the grid suffered much worse damage than that observed during other hurricanes that affected the U.S. in the past decade. This extensive damage added to logistical limitations and the island orography were important factors that contributed to an extremely slow restoration process leading to a very low resilience for the island's power grid. This paper describes all these aspects in detail and supports the explanation of the hurricane effects with photographic evidence collected during a damage assessment conducted in the early December 2017 when about half of the electricity customers were still without service. This paper concludes by exploring some lessons from these observations including potential options to increase resilience, such as the use of microgrids.