When Roland Wessling looked over to his partner Hazel Woodhams he knew instantly that she was dead. What he didn't yet know was that her killer was still in their tent, and that his life was also in danger.
Carbon monoxide, a colourless, odourless gas, had leaked from their extinguished barbecue. Hazel and Roland had been poisoned as they slept.
Half of the world's population use basic carbon-based fuels such as coal, wood and dung to cook and heat their homes, often in poorly ventilated spaces.
The dangers of being too close to an open fire are clear to most of us, but what many people don't know is the potentially fatal threat of a carbon fuel fire that is no longer burning.
Silent killer
In 2011 Hazel and Roland took up camping and bought a new tent. Hazel turned 30 and they decided to take a short trip to the Norfolk Broads for a weekend of camping and canoeing.She had seen the deadly effects of carbon monoxide in her job as a scenes-of-crime officer, and the couple had a carbon monoxide alarm in their home, but they had not thought to bring it with them on their trip.
"We were doing all the cooking, nice and safe, outside the tent," Roland explained. But several hours later they decided to bring the barbecue inside the tent to protect it from rain and passers-by.
"The barbecue was cold to the touch. There was no smoke coming off it, no glowing, it seemed to be completely inactive."