Amusement parks are designed to combine the thrill of fear with the certainty of safety.

Why else would we strap ourselves into small carriages that go at breakneck speeds around a high and uneven track?

Unfortunately for visitors to La Feria Chapultepec amusement park in Mexico, what should have been a fun day out went horribly wrong when the Chimera rollercoaster derailed on Saturday.

This marks the second massive amusement park ride fail in three months. The last one took place at an amusement park in the western Indian city of Ahmedabad.

BBC reports that eyewitnesses said the victims fell from the last carriage of the rollercoaster.

The popular park was closed soon after the incident, and the authorities are now investigating the cause of the derailment.

“This is now in the hands of prosecutors, and prosecutors have already taken the necessary steps for an investigation,” Miriam Urzua, an official from the civil protection organisation, told Reuters news agency.

She said the investigation would be exploring both what happened and who was responsible.

Before we move on to footage of the accident, here’s what it’s like to ride the rollercoaster when things go to plan:

Here’s the terrifying moment the back part of the rollercoaster derails:

Two people were killed, and another two were injured.

Nothing short of a tragedy, and condolences to their families.

[source:bbc]