August 28th Robinson Choquetaype (Macktub) uploaded this graphic on his blog
On the upper right corner you can see that the earthquake took place at 18.40, so time for reaction was very short.
Days after, Robinson followed the topic and travelled to Pisco, the most devastated zone, very near from the epicentre, in order to get information about recue teams. At own proposal and developing a great double spread from the infographics department.
To know more details, I'll better let him talk