The men and women aboard Min Ping Yu No. 5540 had crossed the strait looking for work and a better life. In the years after Taiwan lifted martial law in 1987, movement across the strait became easier in some respects and the flow of people from Fujian — geographically close, historically connected — increased. Those who came without authorization faced detention and repatriation. The Taiwan Garrison Command, the security body responsible for managing this, used commandeered mainland Chinese fishing boats as transport, without notifying mainland Chinese authorities that the crossings were taking place. The people in the hold were not combatants or criminals in any conventional sense. They were workers, many of them fishermen from coastal Fujian, caught between two governments that refused to communicate directly with each other.

The Taiwan Garrison Command's standing procedure was to seal deportees into the holds for the crossing, escorted by Taiwanese military vessels. On Min Ping Yu No. 5540, twenty-seven people were reportedly confined in a single cabin approximately one meter high and three meters wide. The hold was closed, overcrowded, and without adequate ventilation, water, or food. The summer heat on the strait in late July is punishing. The exact sequence of events during those hours cannot be fully reconstructed, but the outcome is documented: twenty-five people died of suffocation before the boat reached Fujian. Fifty-one survived. Three weeks later, on August 13, another vessel being escorted in a similar operation — Min Ping Yu No. 5202 — was struck by a Taiwanese naval destroyer escort; twenty-one of the fifty people on board were killed.

The incident created enormous pressure on both sides of the strait to acknowledge what had happened and establish some form of process to prevent it from happening again. The ROC government had adhered to the Three Noes policy — no contact, no negotiation, no compromise with the People's Republic of China — which meant the repatriation operations had been conducted without any official coordination with mainland authorities. The deaths made the cost of that posture impossible to ignore. On September 12, 1990, the Red Cross Society of the Republic of China and the Red Cross Society of China signed what became known as the Kinmen Agreement, establishing humanitarian procedures for repatriation through Kinmen Island. It was the first formal agreement of any kind reached between institutions representing the two sides since 1949. The agreement did not end the underlying tensions, but it created a channel — and it existed because of the people who died in that hold.

The Min Ping Yu No. 5540 incident is not widely taught or commemorated. It falls into the difficult category of events that neither side of the strait has found it straightforward to memorialize: the deaths occurred under the authority of the Taiwan Garrison Command, an institution whose broader history in Taiwan is itself contested, and they happened to people from the mainland at a moment of acute cross-strait hostility. What the historical record establishes is this: twenty-five people came to Taiwan seeking opportunity, were detained, placed in conditions their bodies could not survive, and died at sea on a summer night in 1990. Their names have not been widely publicized in English-language sources. The official response, however incomplete, produced a mechanism — the Kinmen Agreement — that formalized something the tragedy had made clear: people being moved across the strait deserved at minimum the basic conditions necessary to stay alive.