If a US supply drop zone lost power while under Contruction (example: disabled by player owned microwave tank force fire) then the first supply drop will happen immediately if construction finish at that state without waiting the initial 2 minutes.

causing the drop zone to (in-a-way) refund $1500, (or $1650 with supply chain upgrades). cutting it cost down to 1000 (or 850 with upgrade)

(this could also be related to the particle cannon gate animation glitch)