Guild Wars 2

In some of the events in Wayfarer Foothills one needs to block a vent using a ice block. I’ve run all over the place looking for them and no cigar. Where does one find these?

If the event works anything like the ones in Diessa Plateau, the Ice Blocks will drop from the Ice Elementals guarding each vent. The Ice Elementals respawn around the vent periodically, unless the event is bugged and they’re not spawning.