def sfiles_to_event(sfile_list):
    event_list = []
    sort_list = [(readheader(sfile).origins[0].time, sfile)
                 for sfile in sfile_list]
    sort_list.sort(key=lambda tup: tup[0])
    sfile_list = [sfile[1] for sfile in sort_list]
    catalog = Catalog()
    for i, sfile in enumerate(sfile_list):
        event_list.append((i, sfile))
        catalog.append(readheader(sfile))
    write_event(catalog)
    return event_list