On July 25–26, 1956, the Andrea Doria sank after colliding with the Stockholm. While both ships were detected on radar, each mistook the other’s actual course; the Andrea Doria was traveling in a heavy fog that the Stockholm would soon encounter, and mistakes were made reading the radar. While the Swedish liner decided on the standard port-to-port pass (on the left), the Andrea Doria elected to pass on the starboard (right) side. At a distance of approximately two nautical miles apart, the liners finally established visual contact. It soon became apparent that they were heading toward each other. Traveling at a combined speed of some 40 knots, they were unable to make the necessary adjustments to avoid a collision. At approximately 11:10 pm on July 25, the Stockholm struck the starboard side of the Andrea Doria, which sunk the next day