It wasn't Enriquillo-Plantain Garden after all:
BBC News - Haiti quake was caused by previously unknown fault
BBC News - Haiti quake was caused by previously unknown fault
Eric Calais from Purdue University in Indiana, presented the findings at an scientific meeting in Brazil.
At the American Geophysical Union's Meeting of the Americas in Foz do Iguacu, he explained that the earthquake was more complicated than previously thought.
He said that the first "give-away" was the fact that there was no surface break along the known Enriquillo fault. This led to a search for other faults or fractures in the Earth's crust, which may have slipped and caused the event.