Lava from Kilauea volcano has destroyed three long-abandoned structures in the largely empty Royal Gardens subdivision since Sunday as a young tube system continued to funnel lava into the area.

Slow-moving 'a'a flows have repeatedly entered the subdivision and stalled in recent weeks, but scientists at the U.S. Geological Survey said the tube system is now providing a continuous supply of pahoehoe lava to the area above the subdivision.

The flow once again entered Royal Gardens Sunday, and branched into two main lobes within the subdivision, with one following Royal Avenue and the other following the adjacent Prince Avenue.

By Tuesday the flow had penetrated about two-thirds of the way through the subdivision and burned two buildings, and by this afternoon had burned a third abandoned structure, scientists said.

The Royal Gardens subdivision originally had 1,827 lots, but much of that property has been covered by flows over the past 25 years.

The volcano has destroyed an estimated 66 homes or other structures in Royal Gardens since 1983, and only one full-time and one part-time resident remained there at the beginning of this year. The two use motorcycles to get access to the area, which is not served by a road.

Neil Gyotoku, spokesman for Big Island Civil Defense, said the two remaining residents told authorities they plan to remain in the subdivision.

"We told them from last week this thing was coming down and they may want to think about getting out or getting their stuff out, but they said don't worry about it," Gyotoku said.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.