Cliff gives way at "firehose" lava flow as tourists watch

This Jan. 29, 2017 photo provided by the U.S. Geological Survey shows a lava stream pouring out of a tube on the sea cliff at the Kamokuna ocean entry at the Hawaii Volcanoes National Park on the Big Island of Hawaii. A dramatic "firehose" stream of lava is shooting out of a sea cliff on Hawaii Island, splashing into the Pacific Ocean below and exploding upon impact. A USGS geologist with the Hawaii Volcano Observatory said Wednesday, Feb. 1, 2017 that one of the biggest concerns is a large "hot crack" above the lava tube, running parallel to the sea cliff and makes the land susceptible to collapse. (U.S. Geological Survey via AP)

HONOLULU (AP) — A section of sea cliff above a massive "firehose" lava flow on Hawaii's Kilauea Volcano has collapsed and splashed into the ocean as tourists and geologists watched on.

A large crack in the section of cliff above the gushing molten lava stream gave way Thursday afternoon as scientists stood just yards away. A tour boat was cruising by when the collapse happened. Video shows guests gasping and screaming as the huge piece of land splashes down in front of them, sending debris high into the air.

The collapse stopped the heavy stream of lava known as a firehose flow that had been arching out from near the top of the cliffs.

The USGS warns that a portion of unstable cliff is still attached and could break off at any time.