Hawaii authorities scrambled to evacuate people from their homes as lava spurted anew from fissure 20 on Saturday.
The blistering-hot stream was created after a new explosive volcanic eruption sent a two-mile-high ash plume skywards at 4pm local time on Saturday (3am Sunday BST).
Fast-flowing molten rivers crossed Highway 137 at the 13-mile marker around 10.30pm local time, with a second flow stopping just 400 metres short of the road.
Hawaii County Civil Defense Agency confirmed it had closed the the key highway between Kamaili Road and Pohoiki Road, while Kamaili Road was closed between Highway 130 and Highway 137.
Residents were advised to evacuate, while National Guard soldiers airlifted trapped residents from the Puna area after earlier lava isolated 40 homes.
Shocking aerial images showed the scale of the fast-moving rivers of fire.
In one picture, the flames of a burning house could be clearly seen amid a burning sea of red as the lava reached homes in Pahoa, Big Island.
So far 40 homes have been destroyed and thousands of people have been evacuated.
No-one has died but the Kilauea volcano has claimed its first serious injury.
Lava splatter shattered a man’s leg after he was hit on a third-floor balcony in Noni Farms Road.
Has the lava reached the ocean?
Officials also confirmed at about 11pm local time that lava had reached the Pacific Ocean, creating an additional threat of haze.
Laze, a blend of lava and haze, is a deadly corrosive gas “formed when hot lava hits the ocean sending hydrochloric acid and steam with fine glass particles into the air”.
The white cloud killed two people in 2000 when seawater washed across active flows, according to USGS.
Acid rain from the cloud has a PH level between 1.5 and 3.5, and “even the wispy edges of it” can cause breathing problems, skin and eye irritations.
Residents are already on alert for high emission of vog (volcanic smog) after life-threatening toxic sulphur gas spewed from cracks in the grands.
Officials are now going door to door to urge people to leave their homes, while the Hawaii National Guard has warned of possible mandatory evacuations.
Plans are currently underway to open up an alternative escape route blocked by fire as parts of Highway 137 were closed. Another major route, Highway 130, is also at risk.
A United States Geological Survey scientist warned Kilauea was becoming increasingly explosive, after lava fountains reach 20-feet high.
Wendy Stovall said: ”Summit magma has arrived.
“There is much more stuff coming out of the ground and its going to produce flows that will move much further away.”
Around 2,000 people have been moved out of Leilani Estates and Lanipuna Gardens since the major eruptions began on May 3.
Kilauea volcano is one of the most active volcanoes in the world and has been in near constant eruption since 1983.