okay after doing the parkour it leads to the weird garage area i found earlier, though i am not super sure how to get that way back as it is just a giant empty room, (probably what the under construction is about) but maybe breaking 2 boxes to get 2 guns and then using the first one to get on the first ledge and then the other to get up the other ledge. though the second one is a lethal drop so i am not quite sure how to get up that far safetly (probably cant) also i dont know how to spoiler these texts :(