GoogleDNS down. .US down zone

We’ve been observing how the .US zone lies for an hour now,
tweeting that GoogleDNS is lying, maybe these are related things.

There are no explanations so far.
Twitter recommends switching to OpenDNS, it works
- 208.67.222.222
- 208.67.220.220

Update: it seems to have risen.
According to indirect indications, the .US zone lay somewhere from 19:10 to 20:00 UTC