Two sister and brother Thursday suffocated to death at Mansehra when they left the gas heaters on and after leakage gas filled the room. According to the details, the unfortunate brother and sisters of village Phuldaro of Oghi were studying in Mansehra where Muhammad Usman student of class 9 and Aisha Bibi student of the first year were preparing for their examination in the night, both while taking nap temporarily left the gas heater, unfortunately after sometime owing to low gas pressure or leakage gas heater went off and resulting the room was filled with the gas and both have suffocated to death. In the morning when one of the family members opened the door to call the children for breakfast he found them dead. The dead bodies of brother and sister were shifted to their native town where in the evening the funeral prayer was offered. This was the first death caused by the sui gas leakage during the current winter season while during the last year more than a dozen people have lost lives owing to gas leakage, suffocation by gas leakage and fire caused by gas in the district Abbottabad.