Desktop A, networked through wifi, with a power belken surge protector: Mobo burnt.
Desktop B, wire networked, with a power belken surge protector: NIC burnt.
TimeCapsule, wire networked, with a power belken surge protector: burnt (not sure which component failed).
Router, wire networked, with a power belken surge protector: burnt (not sure which component failed).
Netgear NAS, wired networked through the network surge protector, with an APC UPS (which also provides power surge protection): intact.
Based on the above laundry list, my hypothesis is that the damning surge came from both power line and network. I am not sure why the Belken failed to protect while the NAS protected by the APC UPS survived. One thing is that I put the UPS downstream of another "conventional" surge protector. I wonder if the tandem connection provided some extra protection?