California fire crews make progress against ferocious Oak fire | First Thing

Fire burning near famous national park exploded in size over weekend but crews have achieved 10% containment. Plus, Freya the walrus makes a splash in Norway

Good morning.

Firefighters made progress against a ferocious wildfire in the Sierra Nevada foothills that forced thousands of residents from their homes in the gateway to Yosemite national park.

How big is the fire? Since Friday, the blaze has consumed more than 16,700 acres. More than 3,000 people were under evacuation orders. More than 2,000 first responders were battling the blaze.

Why is Yosemite's Oak fire burning with such ferocity? Experts say dry air, strong winds, parched trees and grass, and soaring temperatures caused the Oak fire to expand rapidly through the rugged foothills in recent days. The area has experienced nearly two weeks of triple digit temperatures and low humidity. Vegetation is at almost record levels of dryness.

How many shark attacks have there been? There have been at least six shark-human encounters along this stretch of coast, none fatal, but some requiring medical attention.

Why has there been a rise in sightings? The rise in encounters is not complicated to explain: warmer sea temperatures mean more food and more reason for sharks to come around.