On May 12, Long Dien District Police (Ba Ria-Vung Tau) said they were investigating the cause of death of two fishermen suspected of gas poisoning after going down to the fish tank to bring an unconscious person out of the tank.

On the same morning, a fishing boat brought the two fishermen ashore at Phuoc Tinh fishing port (Long Dien district) to hand them over to authorities to investigate the cause of death.

Accordingly, before dying, Mr. T. and H. discovered a fellow boatman who was fishing at sea had fainted, so they went down to help.

T. and H. went down to the fish hold to bring the victim up, but then both fainted and fell back down. When the people on the fishing boat brought T. and H. out of the fish hold, both were dead. The initial cause of the two fishermen's deaths was suspected to be gas poisoning in the fish hold.