Thirty-three years ago today, on November 21, 1992 (October 27, 1992 in the lunar calendar), a mass suicide of dolphins took place in Ecuador. On November 21, 1992, the Ecuadorian Institute of Marine Mammals revealed that 57 dolphins committed mass suicide on the beach of Chandui, 560 kilometers southwest of the capital Quito. According to experts at the institute, dolphin suicide is very rare, which is the first time in Ecuador. There is currently no scientific explanation for this phenomenon. It is believed that changes in sea temperature, marine pollution and violent storms may be the main causes of dolphin suicide.