County Managing Director Wil Okabe said his own vacation home in Kapoho Beach Lots was also threatened.
One of the homes lost was that of Hawaii County Mayor Harry Kim, Snyder said.
The official said aerial surveillance of the area showed only the northern portion of Kapoho Beach and the southernmost "sliver" of Vacationland - the latter consisting of only about half a dozen homes - were left unscathed. A morning overflight confirmed that lava had completely filled the Bay.
The lava inundating Kapoho is emanating from Fissure 8, the only volcanic vent that was still belching large volumes of molten rock from the ground as of Tuesday, officials said.
Fissure no. 8 is the only one now active, but walls of a perched pond from the fissure are expected to break and send more lava oozing toward the ocean.
Images captured from a helicopter show seaside homes engulfed in flames as clouds of white steam and hydrochloric acid fumes billow from the water, where red-hot lava was pouring into the ocean.
On Sunday, the flow crept toward Kapoho Bay, a roughly 1,000-foot-wide ocean retreat.
All but a few of the estimated 500 inhabitants of Kapoho and adjacent Vacationland development are now believed to have fled their homes, an agency spokesman said.
"He was very depressed", Okabe said of how Kim felt about losing his vacation home.
Kathy Emery, who evacuated from her 5-acre farm in Kapoho, said she doesn't know if she has a home to go back to. She said it would be some time before precise losses were confirmed. Police said a 55-year-old man was arrested last week after he circumvented a traffic checkpoint and crashed his vehicle into a hardened lava flow.
More eruptions are possible in the coming months as the deflation process continues, Cindi Preller, geologist and duty scientist at the Oahu office of the National Oceanic and Atmospheric Administration, told ABC News.