Survivors of five sightseeing helicopter passengers killed in a mid-air crash over the Hudson River last summer have sued the tour operators and other defendants in federal court in Newark, N.J.

The decedents, members of two families from the vicinity of Bologna, Italy, departed from the West 30th Street Heliport in Manhattan on Aug. 8 and collided with a small plane at 1,100 feet. Both aircraft plunged into the river near Hoboken, N.J., killing everyone on board.