http://www.newsweek.com/kilauea-volcano-eruption-new-volcano-hawaii-1003766

Kilauea, the most active volcano on Hawaii, has been in continual eruption since 1983. It entered a new phase in early May when fractures along a rift on the eastern side of the volcano opened during a series of earthquakes—some of which became volcanic fissures from which lava erupted. 

These fissures allowed magma that had been ponded in a lava summit lake to drain onto the ground surface as lava flows lower down the mountain. This was close to a residential subdivision known as Leilani Estates, where a new volcanic cone has since developed.