On 16 April 2016, a magnitude (Mw) 7.8 earthquake struck coastal Ecuador and generated more than 1,500 aftershocks as of June 19, 2016, many with Mw exceeding 6. The epicenter of the main shock was located approximately 29 km south-southeast of Muisne, and had intensities of VIII and IX over a large affected region in the provinces of Esmeraldas and Manabí. More than 10,500 buildings were damaged or collapsed in urban areas, and more 8,100 in rural areas. The affected buildings were primarily concentrated in the municipalities of Bahía de Caráquez, Calceta, Canoa, Chone, Manta, Muisne, Pedernales, and Portoviejo. Most of the affected buildings were reinforced concrete frames with unreinforced masonry infill and partitions, and most of the observed buildings had typically 4 to 5 stories except in Bahía de Caráquez were many 8- to 10-story buildings were observed. Extensive non-structural damage was observed, as well as structural damage to the RC frames. Ground motion characteristics varied considerably from the strong motions recorded in Pedernales, which had intense east-west motion and an acceleration pulse of 1.4g, to the motions recorded in Chone, which had much lower peak ground accelerations and large energy content in the 0.3 to 1.0 Hz range. Observations of damage are correlated with characteristics of the recorded ground motions in several of the affected cities.