>> i feel like we are. >> reporter: as the lava moves, the group's routine stays largely the same. fly -- >> just at about 100 meters altitude. >> reporter: -- take photos, upload the data. so this is a base map. and analyze it and repeat. this week they watched as a massive fast-moving lava flow cut off highway 132, creeping down it for two miles, leaving a pile of shifting lava some 10 feet high. >> it will be seemingly cool at the surface, but there's actually still a lot of heat in there. >> reporter: some of that lava is headed toward another highway, the only remaining escape route for some communities. officials are now given some neighborhoods an ultimatum -- leave or be prosecuted. >> this is an order that is a formal order that does mandate that they leave.