At least 70 people, most of them passengers on the Argentine Railways "Firefly Express" train, were killed in a head-on collision with a freight train. The express train was carrying 1,040 passengers who were returning to Buenos Aires from the vacation resort of Mar Del Plata. As it was approaching the station at Altamirano, 65 miles from Buenos Aires, the express crashed into a steam-hauled freight train. Both locomotives exploded, spreading burning diesel fuel over a wide area and setting the first three-passenger cars on fire. Rescue workers were unable to search for survivors for several hours because of the intensity of the blaze. A police doctor, giving an estimate of 34 deaths, conceded that "There is no telling how many bodies burned up in the fire".