When did Thaumanova blow up?
Unfortunately we don’t have a clear date. However, dialogue in Rata Sum shows that it was relatively recent as cause (and even effects) was/were unknown. So it would be not too long before the events of the Personal Story/core game starts. So 1324 is most likely scenario.
Dear ANet writers,
Stop treating GW2 as a single story. Each Season and expansion should be their own story.
Stop treating GW2 as a single story. Each Season and expansion should be their own story.
Survivors of the explosion are still living in tents nearby. I would take this as another indication that the event was very recent. Perhaps some of the NPCs there have dialog or overheard conversations that would help you piece together your back story.