Salih (peace be upon him) was sent to the people of Thamud, calling them, "O my people, worship Allah; you have no deity other than Him" (7:73). Thamud were a people who carved homes into the mountains and lived in security and ease (7:74, 15:82).
When they demanded a sign, Allah brought forth a she-camel as a clear sign, and Salih warned them to let her graze freely on Allah's earth and not to harm her, and to share the water between her and themselves on appointed days (7:73, 26:155). He cautioned that harming her would bring a terrible punishment.
But the most wretched of them conspired and hamstrung the she-camel, defying Salih and daring him to bring the threatened punishment (7:77, 91:14). Salih told them to enjoy themselves for three days, a promise that would not be belied (11:65).
Then the blast (sayhah) seized them, and by morning they lay lifeless in their homes (11:67, 7:78). Allah saved Salih and those who believed with him, and Thamud became another sign for those who reflect (27:53).