Authorities rushed to a residence in Coonabarabran – a small town in central-west New South Wales – after a 66-year-old grandmother called the Department of Communities and Justice to say her grandsons were dead. The woman's call at around 1.30pm on Monday, which also requested help, prompted a welfare check by emergency services who arrived about 30 minutes later. Upon entering the property, authorities discovered two brothers aged six and seven deceased. Further tragic details of the incident emerged after The Sydney Morning Herald reported the grandmother attempted to take her own life when police arrived. After being arrested at the scene, she spent the night under police guard while an assessment was conducted at a local hospital. Police informed media it appeared the boys had been suffocated and the woman is expected to be charged with the murders of her grandchildren. Now, in a tragic twist it has emerged the six-year-old boy had been battling cancer since birth, according to The Daily Telegraph . The news of the two boy's deaths has shocked the small community which has a population of less than 3,500 and is located 540km north of the nation's capital, Canberra. It was announced a post mortem will be carried out today. Peter, a karate instructor who taught the boys, told The Daily Telegraph: "To be honest, when I found out what had happened yesterday, I was amazed. Their grandmother would come along to class with them and help out. She was so willing to get in here and hold the bags, with all the different kids kicking the bags and stuff, she didn't shirk it." NSW Police Commissioner Karen Webb said resources would be made to help local police and she described the deaths as a "terrible, terrible tragedy". The commissioner confirmed the State Crime Command has also sent detectives from Sydney's homicide squad to assist local police in the investigation. "This is a truly horrific tragedy involving children so young," Commissioner Webb said. "Our hearts go out to the family of these boys, and to the entire community who will be devastated by what has happened today." She added that support would be offered to first responders, the distraught family and the wider community. Heart-breaking tributes for the brothers were shared on social media as the tight-knit community woke to the tragic news. "Two little firecracker kids," one relative wrote. "They were amongst it all, 100 miles an hour, involved in soccer, karate, wild as march hares and cute as buttons! It is so devastating for all. It makes me sick to think how their last minutes were spent." Outside of the small town, the state's leader Premier Chris Minns described the day as "terrible" and claimed the whole state would share in the isolated community's grief. He said: "What has occurred is terrible and as a state we share in the community of Coonabarabran's grief at the loss of two young boys who had their entire futures ahead of them. "I can not begin to imagine the heartbreak their loved ones are currently feeling, including their family, friends, and teachers. I thank the local officers who attended the scene for their professionalism and bravery in the face of such a horrible event." Strike Force Darnum has been set up to investigate the tragic incident. For emotional support, you can call the Samaritans 24-hour helpline on 116 123, email jo@samaritans.org , visit a Samaritans branch in person or go to the Samaritans website. For the latest breaking news and stories from across the globe from the Daily Star, sign up for our newsletter by clicking here .