Two Men, a Coal Angithi and a Closed Room
A constable is the first responder to a rented room in a crowded colony. The door was bolted from inside and had to be forced. Inside, two men lie unconscious on a mattress; one shows a strikingly pink, cherry-red face. A coal angithi is still smouldering in the corner, the window is sealed with plastic sheeting, and the ventilation brick is blocked with cloth. There is no sign of a struggle and nothing appears stolen.
The constable's colleague says: 'They simply used up the oxygen in a closed room, that is all. There is nothing to investigate here - open the door, drag them out and let the families take them.' He also says that since carbon monoxide is heavier than air, only the low vent near the floor needs to be opened, and that anyone can crawl in to pull the men out.
1. Explain what actually happened in the room, and identify precisely where the colleague's explanation is incomplete.
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What the angithi does in a sealed room. Coal burns carbon to carbon dioxide when oxygen is plentiful. Once the room is closed and the air is depleted, combustion becomes incomplete and the dominant product is carbon monoxide (CO) - colourless, odourless and tasteless, so there is no warning at all.
Why CO kills. CO binds the iron centre of haemoglobin with an affinity roughly 200–250 times that of oxygen, forming carboxyhaemoglobin. Oxygen is still present in the room and still enters the lungs, but it cannot be carried. CO also shifts the oxygen–haemoglobin dissociation curve to the left, so whatever oxygen is carried is not released to the tissues. The result is severe tissue hypoxia - the brain goes first, which is why victims simply fall asleep.
The cherry-red face is the classic sign: carboxyhaemoglobin gives the skin and lips a pink flush instead of the blue (cyanotic) colour seen in ordinary suffocation. Two people unconscious beside a smouldering angithi, in a sealed room, with one cherry-red, is the textbook picture.
Where the colleague is wrong: oxygen depletion did occur, but it is not the cause of death. Saying 'they used up the oxygen, nothing to investigate' mislabels a poisoning as an accident of ventilation, and would let the source - the angithi, its owner and the circumstances - go unexamined.
2. Assess the colleague's two pieces of practical advice: (a) that only a low vent need be opened because CO is heavier than air, and (b) that anyone can crawl in to pull the men out.
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(a) 'CO is heavier than air' - wrong, and the wrong response follows from it.
- Molar mass of CO = 12 + 16 = 28 g/mol; average molar mass of air ≈ 29 g/mol.
- CO is therefore marginally lighter than air, not heavier, and the difference is trivial compared with the mixing caused by draughts and heat. CO does not pool at floor level.
- So a single low vent will not preferentially drain it, and crawling along the floor gives no protection - that advice belongs to genuinely heavier gases such as LPG or propane, which do settle low.
- Correct approach: ventilate the whole space (open door and window, remove the cloth from the vent), and remove the source - carry the angithi outside - only after the victims are out.
(b) 'Anyone can crawl in' - unacceptable risk.
- The room may still hold a lethal CO concentration; a rescuer who enters without protection becomes the third victim within minutes.
- Enter only after the door has been opened from outside and air has moved through, ideally with a second person holding a line at the door, and never alone.
- Do not operate electrical switches or strike a match near coal gas - a spark can ignite accumulated gases.
- Drag the victims out by the arms into open air, call 108 at once, give oxygen through trained EMS personnel, and start CPR if there is no pulse or breathing.
3. The colleague concludes that because there is no struggle, no theft and an obvious accident, no case need be registered. Do you agree? Set out what the constable must actually do at the scene.
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Disagree. An unnatural death is not closed by the absence of a struggle. Carbon-monoxide deaths are also used to disguise homicide, and the angithi may have been lit by someone else, or the room sealed deliberately. The circumstances must be recorded, not assumed.
Actions at the scene, in order:
- Life first: force the entry, ventilate, remove the victims to open air, call 108, start CPR if trained and needed.
- Secure the scene: nobody else enters; the angithi, the cloth blocking the vent, any utensils, glasses or medicine strips are left exactly as found.
- Record: photographs and videography before anything is moved; note the position of the bolted door, the sealed window, the angithi's distance from the mattress, and the approximate time of first response.
- Register: information of a sudden, unnatural death must be entered in the daily diary and reported to the SHO for inquest proceedings; the bodies go for post-mortem, and the viscera/blood is preserved for chemical analysis, since carboxyhaemoglobin levels are what confirm CO poisoning.
- Enquire: who rented the room, who lit the angithi, who last saw the men, whether the vent was blocked recently. The family cannot simply be handed the body on the constable's own judgement.
In short: treat it as a death to be investigated until the post-mortem and forensic report say otherwise - the science points to poisoning, and poisoning is exactly the finding that requires an investigation.