Thursday marked the 57th anniversary of when the Swedish passenger ship Stockholm and the Italian passenger ship Andrea Doria collided on the edge of a heavy fog bank off Nantucket, Mass., and the Andrea Doria sank within hours.

The Stockholm crashed into the starboard side of the Andrea Doria near the middle, creating a large hole and breaking open several of the ship’s watertight compartments; 1,660 passengers and crew were rescued, but 46 people died.

The Andrea Doria was the last major trans-Atlantic passenger vessel to sink before aircraft became the preferred method of travel.

Although the exact cause of the July 25, 1956, accident has never been determined, it appears to have been a “radar-assisted” collision, with the officers of the watch on both vessels misinterpreting radar images and taking the wrong actions, according to Bryant’s Maritime Blog, which notes the anniversaries of historic commercial nautical accidents.

Launched in 1951, the Andrea Doria was said to be the biggest, fastest, safest and most beautiful ship in Italy after World War II.

The wreck of the 701-foot Andrea Doria, lying on its starboard side on the bottom 160 feet below the surface, was a popular destination for divers, but it is considered a dangerous ship to explore. The wreck is at 40.49167°N 69.85000°W.

Click here for a clip from a 1988 documentary that shows news footage of the original sinking of the jewel of Italy’s luxury liners.