The lava was seen flowing westwards to the coast in three huge tongues, incinerating everything in their path, including a school.
The largest flow was advancing towards a banana plantation and water reservoir as it crept closer to the main street of the town of La Laguna, travelling at about 200 meters an hour, authorities said.
Lorena, a 42-year-old Laguna resident, raced to salvage furniture and electrical appliances from her parents' home.
"We are nervous, we are taking out the most essential things like mattresses, the fridge," she said, with her family's possessions strewn around the back yard.
The town was evacuated on Monday but emergency workers gave residents a two-hour window to return home and save whatever they could.