Synneva Andersdatter Tossen 1873 emigration

I am searching for the passenger list or ship for Synneva Andersdatter (Tossen/Tyssen) who according to church parish records emigrated in March 1873 from Evanger, Voss, Hordaland? The oral history says she immigrated with her sister Ingeborg and died at sea. The parish emigration record for Ingeborg Andersdatter Tossen is given as May 1875? A contradiction is a marriage date for Ingeborg of 1871 in Norway to John Stromme which would of course make her last name Stromme? Does anyone know if there is a record of those who died at sea - not all passenger lists give this information? Thanks for any help. Kathy