Tadeusz Kosciuszko died in Solothurn on October 15, 1817, at age 71, and was buried in nearby Zuchwil.

A year later, a coffin with Kosciuszko's embalmed body was brought back to the country and ceremoniously deposited in the crypt of St. Leonard in Wawel Castle. In 1832, the coffin was placed in a sarcophagus.