BHOPAL: Toxic fume from celphos tablets meant to protect 250 quintals of wheat from pests spread through a house in Madhya Pradesh’s Gwalior district, leading to deaths of two children aged 4 and 13 and leaving their parents fighting for their lives in hospital.Murar subdivisional police officer Amit Kumar Soni told TOI a cooler kept near the grain might have diverted the fume released by the fumigation tablets towards the family’s rooms. “The 4-year-old died Monday and his 13-year-old sister succumbed during treatment Tuesday.”Satyendra Sharma, his wife Rajni and their children Chhaya, 13, and Vaibhav, 4, were found unconscious on the ground floor of the family home in Gwalior’s Pritam Vihar Colony late Monday. All four were rushed to hospital where Vaibhav was declared dead on arrival while Chhaya died during treatment. Both Sharma and his wife are in hospital and their condition is said to be critical.Soni said, “A case of unnatural death has been registered and investigation is underway. The owner of the house stored wheat on the ground floor and used 25-30 celphos tablets to preserve it. We have taken samples of the gas, and forensic teams are conducting tests to find the exact cause of death.”