A system that should have passed on a warning to a Pacific Island about the imminant risk of a potentially devastating tsunami failed, a disaster official said Thursday.

"Nobody got a warning through the emergency satellite system in our meteorogical office," Mali'u Takai, deputy director of Tonga's National Disaster Office, told The Associated Press in a telephone interview.

A massive magnitude 7.8 earthquake rocked Tonga on Thursday, triggering tsunami warnings that raised jitters as far away as Hawaii and New Zealand.

No massive waves materialized and no major quake damage was reported.

"Judging by the location of the epicenter we would have been caught out without any warning at all because of the systems malfunction," Takai added.

Takai's comments raised troubling questions about protections in place for inhabitants of the sparsely populated islands scattered thousands of kilometers (miles) across the earthquake-prone region.

The Pacific Tsunami Warning Center says its first alert went out 16 minutes after the earthquake but it was not received in Tonga because of a power failure there.

Gerard Fryer, acting director, said, "There was a problem in Tonga where there was a power outage and they didn't get our initial message."

He said the center needs to work with Tonga to correct the problem. He said he did not know whether the power failure was caused by the earthquake.