[1][2] On the morning of February 1, 1964, a diesel-hauled[1] twelve-carriage holiday excursion train left the seaside resort of Mar Del Plata on its 230-mile journey north to the capital, Buenos Aires.

At Altamirano, 65 miles south of the capital the Firefly Express as it was called, travelling at 100 km/h[1] crashed head-on with a steam-hauled[1] freight train with a thunderous explosion.

Rescue workers were delayed by the muddy condition of the roads in the area following recent rainstorms.

The police doctor, who gave an estimate of 34 deaths, admitted that the exact figure would never be known.

The cause of the disaster was thought to be a fault in the points (switch) which diverted the express into the path of the freight train.