SANTIAGO, Aug 3 (Reuters) - All five workers at Chile's El Teniente copper mine who were trapped in a collapse last week have been found dead, miner Codelco said on Sunday, as it vowed to investigate the cause and improve safety measures.

The bodies of all five miners trapped in a collapsed shaft in the world's biggest underground copper mine for three days have been found and identified, an official said Sunday. Aquiles Cubillos, the lead prosecutor in Chile's O'Higgins region,

Chilean President Gabriel Boric has declared three days of national mourning after the deaths of five mine workers, whose bodies were recovered following a collapse at the El Teniente mine.