Infographic: How mudslides form after a fire

Southern California residents in Glendora and other foothill communities were bracing Monday for potential disaster after Sunday's rain-triggered mudslide on Pacific Coast Highway. Here's how hillsides that have been burned by wildfire become prone to flash floods and dangerous mudslides during heavy rains.

Step 1: Fire burns through growth

Step 2: Rainfall

Step 3: Mudslide

Source: University of Idaho, "After the Fires: Hydrophobic Soils" by Randy Brooks