Somerset : At least seven people are confirmed dead and 51 injured . NEW : More people are feared trapped in vehicles , police say . NEW : Poor visibility and a nearby fireworks display may have been a factor . NEW : The crash in Somerset involved several vehicles , including heavy trucks .
NEW : At least seven people are confirmed dead and 51 injured . NEW : More people are feared trapped in vehicles , police say . NEW : Poor weather and a nearby fireworks display may have been a factor . NEW : The crash in Somerset involved 34 vehicles , including heavy trucks .