A fountain of fire was reported at Kilauea, on the Big Island of Hawaii, after the crater collapse about 2pm on Saturday, with eruptions continuing throughout the following day, KITV-TV reported.
The collapse was accompanied by 150 small earthquakes, the United States Geological Survey said.
The Pu’u ‘O’o crater floor dropped at least 115m during Saturday’s collapse.
Kilauea has been constantly erupting since 1983.