The Hayama Dome Massacre, 2944

This occurred during the final stages of the Solar Republic's suppression of the revolt on Old Mars. Hayama mining base had a number of deep shafts which had been used by the rebels for storing weapons, and towards the end of the revolt it became the last bastion of rebel resistance on Old Mars. With Republic space forces having driven off MAFC attempts to break through to the rebels, the siege of Hayama was one of the last acts of the Earth-Mars War (or the Great War of Liberation, to Martians). A large number of civilian refugees had hidden within the Hayama mines, and estimates place the population at several tens of thousands at the time of the incident.

Briefly, the protective dome of the base was explosively breached (this was 50 years before the terraforming of Old Mars had been completed, and at the time the atmosphere still had too high a CO2 content to be fully breathable). Without enough oxygen masks to go round, most of the refugees were asphyxiated. The dome and mines were then stormed. A series of underground explosions brought down mine shafts, trapping the remaining rebels inside. All of them died before rescue teams could break through to them. The Solar Republic maintains to this day that the demolition of both the dome and the mine shafts was a 'suicide pact' by the defenders, who constituted the most 'die hard' of the resistance forces, and who refused to be taken alive. Martians have always claimed that it was a deliberate massacre by the Earther forces.

Earth has not helped its case by closing the site to visitors, initially as a 'security measure' in the wake of the war, and subsequently as a 'mark of respect' to the estimated 70,000 who died there, when the site was designated a War Grave. It also claimed that the site was still riddled with rebel booby traps which made it too dangerous to enter. It has thus only been in the past few decades, 200 years after the event, that the University of Mars at Cydonia has been granted the necessary permits to begin archaeological work there. However, since the completion of Martian terraforming, most of the mines are now flooded and very little remains above ground, where destruction seems to have been quite extensive. As a result it has been difficult to produce conclusive evidence from the archaeology, while a trawl of the Earth records from the time reveals that most were lost in a fire at the date archives while being stored under the 50-year rule. The truth of the matter thus remains open to debate, and is still a hot political issue on Old Mars.