Three lions, including lionesses, die at a zoo in western Tokyo in what authorities describe as suspected heat-related causes, the Tokyo metropolitan government says. The deaths occur between late July and earlier Monday, during a period of unusually hot summer weather. The metropolitan government states that the animals’ deaths are being linked to heat stress and heatstroke, with investigators reviewing conditions around the enclosures and the lions’ care during the hot days. The report describes the circumstances as part of a broader strain on animals during high temperatures, while also noting that the exact cause is under assessment. Zoo staff and officials are expected to examine environmental controls and the animals’ exposure to extreme heat. No information is provided in the excerpts about necropsy findings or confirmed diagnoses. The deaths raise concern about heat mitigation measures for large animals housed outdoors or in poorly ventilated areas, though the final determination depends on ongoing review by authorities.