[en] The lifetime of the metastable level 3d²¹G₄ in a singly charged scandium has been experimentally investigated at the ion storage ring CRYRING. A laser probing technique has been used for the studies. We also report calculated lifetimes and transition rates for 10 metastable levels in Sc II, including the 3d²¹G₄ state, by calculations using configuration interaction wave functions. The lifetime of the ¹G₄ level is experimentally determined to be τ_exp=2.64±0.18 s and is in good agreement with the theoretical calculation τ_th=2.84 s