When a tunnel providing water to the city of Bogotá, Colombia, partially collapsed in 1997,
it triggered a water shortage, the city government declared a public emergency and initiated a communication program to warn inhabitants of the threat of a crisis.A) it triggered a water shortage, the city government declared a public emergency and initiated a communication program to warn inhabitants of the threat of a crisis. -> we have an IC "When a tunnel providing water to the city of Bogotá....partially collapsed in 1997" and another IC "it triggered a water shortage". It is incorrect form. We need IC, DC.
B) it triggered a water shortage, with the city government declaring a public emergency and initiating a communication program to warn inhabitants of the threat of a crisis.-> Same as A.
C) triggering a water shortage, the city government declaring a public emergency and initiating a communication program to warn inhabitants of the threat of a crisis. -> We are in better shape, with IC, DC form. But, the city government declaring ....is incorrect. We need past tense.
D) triggering a water shortage, the city government declared a public emergency and initiated a communication program to warn inhabitants of the threat of a crisis. -> It is better than C. Let's keep it.
E) triggering a water shortage, a public emergency was declared by the city government and a communication program initiated for warning inhabitants of the threat of a crisis. -> "Something happened then someone took actions" is a better form, not "actions are taken by someone". incorrect.
So, I think D.