HILO >> Brush fires ignited by lava forced evacuations south of Leilani Estates in Lower Puna on Saturday, as a separate flow was pushing its way through the Malama Ki Forest Reserve toward the ocean, threatening to cross Highway 137 and overrun MacKenzie State Recreation Area, county officials said.

Residents on Kamaili Road were told to immediately evacuate and most had already moved, but county and state fire units were going door to door to check if they needed assistance, according to Hawaii County Civil Defense.

Saturday also saw the first report of an eruption-related injury since the Kilauea volcano began spewing lava May 3. Hawaii County Fire Department officials said a homeowner on Noni Farms Road was on his third-floor balcony when he got hit on the shin with lava spatter, shattering the lower portion of his leg.

These “lava bombs” can weigh as much as a refrigerator and even small pieces of spatter can be lethal, officials said.

Thousands of residents from Leilani Estates, Lanipuna Gardens and other communities south of Pahoa have been evacuated as a result of volcanic activity and toxic fumes, many seeking shelter at three emergency centers set up by the American Red Cross. As of Saturday, 44 structures, mostly in Leilani Estates and Lanipuna Gardens, had been destroyed by lava pouring out from a series of fissures.

Government officials spent much of Saturday focused on the flow making its way southeast of Leilani Estates about half a mile from Highway 137, also known as the Kalapana-Kapoho, or Red, Road. No structures were in immediate danger, officials said.

The first weeks of the eruption saw pasty, crumbly, slower-moving aa lava oozing slowly through the fissures. But that changed Friday afternoon, scientists said, when preliminary results from a testing sample showed a different composite of lava, the smoother pahoehoe variety that is generally fresher, hotter and faster.

It was the pahoehoe variety that poured out of fissure 20, forming a fast-flowing river of lava that made its way below Leilani Estates, across Pohoiki Road and then onto Malama Ki Place Friday night, cutting off access for residents still in their houses. Four of the stranded were picked up by Hawaii Fire Department and National Guard helicopters.

About 40 homes are on Malama Ki Place. A Civil Defense official went door to door and the agency determined that everyone was accounted for.

On Saturday, that same flow made its way toward the ocean through the forest reserve. Civil Defense reported the flow had traveled about 1,000 feet during a one-hour period, dramatically faster than the 12 hours it took to cover the same distance overnight.

As of 9 p.m., Civil Defense reported the flow from fissure 20 had split into lobes, both headed toward the 13-mile marker of Highway 137. One was approximately 2,000 feet away and traveling about 328 feet per hour. The second flow front was 2,460 feet from the highway and moving at the same speed.

ALTERNATE ROUTE OUT

Highway 130, the Pahoa-Kalapana Road, provides an alternative route for lower beach communities from Isaac Hale Park to Kalapana, so it would not be dire if lava cut access to Highway 137. But with lava still so active in the Lower East Rift Zone, state transportation officials said they were working on a plan to reopen Chain of Craters Road as an emergency exit route in case Lower Puna residents become isolated.

Jessica Ferracane, spokeswoman for Hawai‘i Volcanoes National Park, said the state Department of Transportation is working with federal and local authorities to remove lava from 2016-17 flows that covers portions of Chain of Craters Road so the road can be reopened in case highways 130 and 137 are cut off by volcanic activity.

She said about one mile of lava needs to be removed before the road will be accessible, and that would take four to six weeks.

The change in composition of the magma is being watched closely by scientists and Civil Defense officials.

Carolyn Parcheta, a Hawaiian Volcano Observatory geologist, said it would be troubling if flows head east of Lanipuna Gardens.

“To me that is a very scary scenario, and that’s what concerns me most is that people might be trapped,” she said Saturday.

Parcheta noted that on Friday, the flow moved very quickly, almost a half-mile an hour, as it cut off access to Pohoiki Road and Malama Ki Place.

“That’s hard to get around quickly if you don’t know it’s coming,” she said.

Lava dumping into the ocean would pose new hazards. Civil Defense warned that residents should be aware of the danger from “laze” if lava enters the ocean. Laze occurs when hot lava hits seawater, sending hydrochloric acid and steam with fine glass particles into the air.

Laze plumes travel with the wind and can change direction without warning.