A transmission fault outside DC on 25 July dropped 3.1 GW of AIDC load in roughly 30 sec. The resulting 3.49 GW surplus drove a voltage spike across the entire PJM system, from Northern Virginia to Chicago, taking 11 minutes to clear. These facilities act as synchronized, low-inertia loads. Their protective schemes trip nearly together, turning a local contingency into a regional frequency /voltage event. As AIDCs approach a projected 24% of PJM demand by 2040, coincident disconnects become a systemic risk rather than an edge case. On-site storage sized for full-load bridging, plus inverter controls that provide synthetic inertia + ride-through, can absorb the step change w/out cascading further trips. The episode shows that compute density & grid dynamics now require joint design, not sequential hardening - our focus 🙌