Ye aparently they couldnt fix it in time, and went to bed i guess. hope they wake up soon to fix it!
PTR does not receive the same priority as the Live servers. When a problem occurs on the standard Live servers, there are a number of Blizzard employees on-call that will have to drop whatever it is they're doing and come in to address the issue.
PTR will never receive the same attention. They will do what they can, but will not pay overtime and approach the issue with the same sense of urgency.
PS: Blizzard is headquartered in Irvine, California. They should arrive between 6am-8am PST. Whatever the issue, they're likely on it as I type this.