Confined space – multiple fatalities

IMCA has received information about a confined space incident in there were multiple fatalities. The incident occurred at an oil well on land. A workman entered a water tank that contained water mixed with nitrogen, and collapsed. A co-worker entered after him in an attempt to rescue him, and likewise collapsed. He was followed by two further workers who also collapsed.

Water tank where incident occurred
Water tank where incident occurred

The supervisor realised that four workers were inside the tank, gave orders to drain the tank and then asked two further personnel to enter the tank for rescue purposes using safety lines.

Three of the rescued personnel were found unconscious and one semi-conscious. All four were evacuated to a nearby clinic for first aid and then to hospital for further treatment. The three men found unconscious did not recover and were declared dead by a local doctor.

Investigation revealed the following:

  • Procedures were not followed
  • There was no permit to work for confined space entry arranged in this case;
  • There were no multi-gas tests conducted (LEL, O2, CO₂ and H₂S) before confined space entry.
  • Personnel did not wear appropriate personal protective equipment (PPE) for task;
  • The rescue attempt was not properly planned or thought through.