Sirio was a 4,141-GRT passenger steamer built in 1883 by Robert Napier and Sons of Glasgow for Società Italiana di Trasporti Maritimi Raggio & Co. of Genoa.

[5][6][7][8] Sirio sailed from Genoa on 2 August 1906 under the command of captain Giuseppe Piccone, bound for Buenos Aires via Barcelona, Cadiz, Las Palmas, Cape Verde, Rio de Janeiro, Santos and Montevideo; at the departure from Genoa she carried a crew of 127 and 570 passengers, and a further 75 passengers joined the ship in Barcelona.

The boilers exploded, and "dead bodies began to float past the French steamer, and those on board could hear the shrieks of the drowning.

[19] Panic soon broke out onboard; some of the lifeboats had been damaged in the grounding, and several others were swarmed by the panicked passengers and swamped or capsized, resulting in the death of their occupants.

The ship broke in two and sank completely after being grounded for nine days, and "dozens of decomposing corpses were released in the turbulence" including "the body of a very young girl still clutching her toy bucket.

This alleged "illicit traffic" was offered as one explanation for the captain's behavior, which "left much to be desired", and has also been cited as a reason to consider the official death toll as unreliable.

[52] Among these shipwrecked ones the priests prayed to heaven,And they gave them their last benediction.Fathers and mothers, they kissed their dear children,And then they sank beneath the waves of the sea.

"[53] The Spanish poet Santiago Delgado published a memorial "legend" about the disaster in a collection of eight pieces about the Mar Menor, the lagoon just north of Hormigas Island.