Island on fire

Toxic gases rise near an abandoned home in the Leilani Estates subdivision near Pahoa, Hawaii Friday, May 18, 2018. Hawaii residents covered their faces with masks after a volcano menacing the Big Island for weeks exploded, sending a mixture of pulverized rock, glass and crystal into the air in its strongest eruption of sandlike ash in days. (AP Photo/Jae C. Hong)

Evacuee Michael Hauanao, 32, watches video on a phone at a makeshift donation center as clouds turn red from lava flow in the Leilani Estates subdivision. (AP Photo/Jae C. Hong)

A young boy photographs the sky turned red from lava flows in the Leilani Estates subdivision near Pahoa Friday. (AP Photo/Jae C. Hong)

As lava activity erupts in the background, cars drive down Highway 132 Friday near Pahoa. (AP Photo/Marco Garcia)

Peter Vance, 24, photographs lava erupting in the Leilani Estates subdivision near Pahoa, Hawaii Friday, May 18, 2018. Hawaii residents covered their faces with masks after a volcano menacing the Big Island for weeks exploded, sending a mixture of pulverized rock, glass and crystal into the air in its strongest eruption of sandlike ash in days. (AP Photo/Jae C. Hong)

Lava erupts in the Leilani Estates subdivision Friday. (AP Photo/Jae C. Hong)

A resident photographs toxic gases emitting from cracks in the Leilani Estates subdivision near Pahoa, Hawaii Saturday, May 19, 2018. Two fissures that opened up in a rural Hawaii community have merged to produce faster and more fluid lava. Scientists say the characteristics of lava oozing from fissures in the ground has changed significantly as new magma mixes with decades-old stored lava.(AP Photo/Jae C. Hong)

Flowers are placed on the road as an attribute to the Hawaiian volcano goddess Pele in the Leilani Estates subdivision near Pahoa, Hawaii Saturday, May 19, 2018. Two fissures that opened up in a rural Hawaii community have merged to produce faster and more fluid lava. Scientists say the characteristics of lava oozing from fissures in the ground has changed significantly as new magma mixes with decades-old stored lava.(AP Photo/Jae C. Hong)

HOLLYN JOHNSON/Tribune-Herald

A family watches the glow from a fissure Saturday from Highway 137 near Kapoho Vacationland.

HOLLYN JOHNSON/Tribune-Herald Residents watch plumes rise from Highway 137 Saturday in Kapoho.

HOLLYN JOHNSON/Tribune-Herald Civil Defense informs drivers of the threat of lava crossing Highway 137 Saturday in Kapoho.

HOLLYN JOHNSON/Tribune-Herald Members of Hawaii County Civil Defense, Hawaii Police Department and USGS monitor lava that is threatening Highway 137 Saturday in Kapoho.

HOLLYN JOHNSON/Tribune-Herald A truck drives toward Hilo loaded with belongings Saturday on Highway 137 in Kapoho.
HOLLYN JOHNSON/Tribune-Herald Residents watch plumes rise from Highway 137 Saturday in Kapoho.

A helicopter overflight of Kilauea Volcano’s lower East Rift zone around 8:18 a.m. Friday showed ‘A‘ā lava flows emerging from the elongated fissure 16-20 channel. USGS photo

HILO — A fiery river of molten rock was on a collision course Saturday night with Highway 137 and the Pacific Ocean, prompting officials to warn about hazardous volcanic gas known as “laze” if lava meets the sea.