At 8:00 p.m. on 7 December 1966, and during extreme weather conditions, with southeast winds blowing at Force 9 on the Beaufort scale, Heraklion travelled from Souda Bay, Crete for Piraeus, after a two-hour delay, allegedly in order to embark a refrigerator truck that, according to most accounts, contributed to the sinking.

After midnight, the Heraklion was crossing the Myrtoan Sea amidst high waves and heavy winds that were steadily gaining speed.

At 2:00 a.m., halfway through the voyage, sailing six miles off the small rocky island of Falkonera, the aforementioned refrigerator truck, which was carrying oranges and was either left unsecured or was strapped loosely, started to slam into the midship loading door, which eventually gave way and opened, and the truck plummeted into the sea, where it was found floating the next morning.

The Greek Ministry of Mercantile Marine was underequipped to handle the necessary communications, while the port authorities of Piraeus, Syros and other islands also reported that they were unable to offer assistance due to lack of equipment.

The Ministry of Defence reported that a ship of the then-Greek Royal Navy was at Syros, but that it would take three to four hours for it to get underway.

A number of ships, including two British Royal Navy warships northeast of Crete, received the SOS and altered course for the scene.

At 4:30 a.m., RHS Syros was ordered to sea, while an hour later the premier was informed of the situation and the Air Force was alerted.

At 19:00 Leverton and Ashton docked at the port of Piraeus, where a large crowd had gathered to seek information and to wait for the rescue ships carrying survivors and bodies.

A number of United States Navy ships, deployed in the Mediterranean Sea at the time of the sinking, participated with the search and rescue operations.

On 20 March 1968, after a month-long trial, seven defendents received sentences of up to five years in jail, including Haralambos Typaldos, the owner of the company, Panayotis Kokkinos, the general manager, and Nicholas Theodorakis, first mate, as well as the Head of Ship Inspections of the Ministry of Merchant Marine.

Most of the remaining Typaldos ships were taken over and sold, either for scrap or other uses, to meet the costs of damages to the victims and crew severance pay.

[2] Three ships — Hellas, Athinai and Rodos — failed to find buyers and were laid up for 20 years before being sold for scrap and broken up in Turkey in 1989.