At least two people were killed after a derailment by train in Mexico City on Saturday.
Two other people were injured in an incident at La Feria Chapultepec Amusement Park, local officials said.
Eyewitnesses say the victims fell from the last carriage of Chimera's train in the park.
The popular park was closed shortly after the incident and 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 to investigate," Miriam Urzua, a civil defense official, told Reuters.
She stated that the investigation would examine what happened and who was responsible. [1
The fair said he "deeply regrets the horrific incident" and that he has investigated with the relevant authorities.
He also promised to share details of the investigation as they came out.
Video from the scene showed paramedics prone to being injured while police detained viewers away from the closed park.