On the night of July 25, 1956 the eastbound Swedish passenger liner Stockholm collided with the westbound Italian luxury liner Andrea Doria in what was to be described as the world’s first major radar assisted collision at sea. The collision happened approximately 50 miles south of Nantucket at 11:11 p.m. local time.
The Andrea Doria was struck just behind and below the starboard bridge wing and almost immediately took on a severe list of almost 20 degrees to starboard leaving half of her lifeboats unusable. Less than 10 minutes from the time she was struck, the Andrea Doria transmitted an SOS calling for immediate assistance. The loss of her port-side lifeboats might have resulted in a significant loss of life if not for the relatively rapid response of several nearby ships, and by the relative stability of the fatally wounded luxury liner despite carrying a worsening list throughout the night.
Unlike the Titanic disaster of 1912, the total loss of life was relatively small. Only 46 passengers from Andrea Doria died as a consequence of the collision. A total of 1660 passengers and crew were rescued and survived. On Stockholm, five crew members, who were in the area of the bow at the time, also died as result of the collision.
Sources:
Intro Text and Podcast Description:
Halpern, Samuel, "An Objective Forensic Analysis of the Collision Between
Stockholm and Andrea Doria" http://www.titanicology.com/AndreaDoria/Stockholm-Andrea_Doria_Collision_Analysis.pdf ; Page 1
Main Narrative:
Andrews, Evan, "The Sinking of the Andrea Doria" https://www.history.com/news/the-sinking-of-andrea-doria