weiach is first mentioned in 1271. it has belonged to swiss confederation since 1424. since 1962 there has been a gravel industry located in weiach. on 14 november 1990, alitalia flight 404 crashed into stadlerberg mountain near weiach while attempting to land at zurich airport. the crash, which was caused by a faulty navigation system, killed all 40 passengers and 6 crew.