Many people need to understand that Haiti is a special case. The degree of underdevelopment there is so great that its simply incomparable to any other country in the hemisphere. The second poorest country in the hemisphere is either Nicaragua or Bolivia, and both are light years ahead of Haiti.
With that in mind, let's not lose sight than in 2001 El Salvador suffered a 7.9 earthquake (Haiti's was 7.3) and only 1,200 people lost their lives and, compared to Haiti's, relatively little damage.
The DR resembles more El Salvador than Haiti in development at all levels, including construction techniques and enforcement. If anything, El Salvador's 2001 earthquake is a better predictor of what it would be like in the DR, and keep in mind that most of El Salvador deaths were due to a land slide that was triggered by the earthquake.
In 2003 the DR was hit with a 6.0+ earthquake and the damages was relatively few, the deaths did not even reached 100 victims or, to put it another way, Puerto Plata didn't lose not even 1% of its population. The lack of significant victims or damaged caused this earthquake to be completely ignored by the international media. Compare that to Port-au-Prince which lost approximately 20% of its population and an even larger percent of its infrastructure. For further comparison, look into what happened in El Salvador and other countries in the region.
What happened in Haiti is a unique tragedy because Haiti itself is a unique and special case of underdevelopment unlike anywhere else outside of sub-Saharan Africa.
Rest assure, the same earthquake strikes in the DR and the results will be completely different and much less tragic.