First, it was oozing lava streaming into residential areas on Hawaii's Big Island. Now, it looks as if Kilauea might be ready to explode.

Overnight, the U.S. Geological Survey issued a warning that the volcano could turn explosive, as falling lava levels inside the crater bring hot rock closer to cool groundwater. Already, the active peak has seen smaller scale bursts, as rockslides fall into the volcano's crater and create plumes of ash.

Until recently, the biggest threats from the volcano were this slow-moving lava inundation and inhaling the hazardous sulfur dioxide released from the molten rock. Since the volcano began actively erupting last week, more than a thousand people have been evacuated, and at least 26 homes have been destroyed. Dramatic video footage even showed lava engulfing a parked car.