A red alert has been issued for four Tamil Nadu districts in view of heavy rainfall in the state. Three people died in rain-related electrocutions in Tamil Nadu on Thursday after unprecedented torrential rains battered the state, state minister for revenue and disaster management K. K. S. S. R. Ramachandran said. Chennai, Kancheepuram, Thiruvallur, and Chengalepattu are the districts where a red alert, which indicates heavy to extremely heavy rains of over 20 cm in 24 hours, has been issued.