On 23 April 2022, the wood chip carrier China Express berthed at Kutai Refinery Nusantara (KRN) Port. After cargo loading was completed on 25 April, the fumigation team sealed all cargo holds and began releasing methyl bromide (MB), a toxic fumigant, into the holds using electrical equipment. The operation was conducted by 15 personnel, including two certified fumigators. On 26 April, the team started aeration procedures using blower fans and partially opened hatches, in preparation for safe ventilation of the gas.

At approximately 22:45 LT that evening, Helper A entered cargo hold No. 6 without permission or protective equipment to retrieve a dropped gas detector. He collapsed while attempting to exit the hold. In response, Fumigator A entered the hold with only a respirator and attempted to rescue Helper A but also collapsed. Both were later recovered by rescue personnel in full protective gear and showed no signs of life.

Investigations concluded both deaths were due to methyl bromide poisoning. Helper A likely underestimated the danger, despite brief training. Fumigator A, although experienced, used a respirator not suitable for high concentrations of toxic gas, leading to fatal exposure. The incident highlighted critical lapses in safety protocol adherence and the need for proper protective gear and training in hazardous environments.