Slow, but unrelenting - and 2000 degrees.

A river of lava is about to swallow a dozen homes on the Hawaiian Big Island - and there's not much residents can do about it.

CNN's Martin Savidge says it's not clear what path the lava will take.

"Experts say the lava has picked up speed as it heads directly for Pahoa.

"Hawaii's governor signing a request asking for a presidential disaster declaration."