In June 1840, the ship Maria wrecked on Margaret Brock Reef off Cape Jaffa, South Australia. All twenty-six aboard reached shore, but the survivors later split into groups as they attempted to make their way towards Adelaide. Those travelling along the coast entered the territory of the local clan, where they were killed in a series of attacks. The remaining survivors were also pursued and subsequently killed.
Major O'Halloran, acting under orders, rounded up members of the local clan and conducted a summary field trial on the Adelaide frontier. Two men were hanged on 25 August 1840, in what colonial authorities framed as justice for the massacre, but which many historians regard as an act of punitive colonial retribution.
