The line broadly follows the often dry Salado river bed and this was the cause of the problem since the rainwater that fell on March 24 and 25 rushed through its channel, overflowing in many points and taking some 40km of the railway with it on its way to the ocean.

Most of the railway belongs to state-owned mining giant Codelco but a lesser part to the privately-owned Ferronor railway. All trains were run by Ferronor, as a concessionaire over the Codelco-owned sections.

Ferronor and Codelco cannot agree on how much each party should pay for infrastructure repairs, which have been estimated to cost more than $US 50m and could take at least a year to complete. Ferronor has put its staff on paid leave whilst the situation is evaluated. Meanwhile the line's freight traffic is going by road.