His atelier and many of his works were destroyed by the 1827 Great Fire of Turku, which greatly affected Finnberg's life and career. His most famous painting is likely the 1827 "After the Great Fire of Turku". He left Turku and moved to Stockholm soon afterwards. Other than some works inspired by the fire, Finnberg struggled to make a living as an artist until his death on 28 June 1833.