As the threat of a chemical tank explosion in Garden Grove dragged into its third day, officials announced a potentially positive new development — a crack was seen on the tank.

California emergency officials were conducting an overnight mission to measure the pressure in a tank at risk of leaking or exploding, which has forced evacuation orders for more than 40,000 Orange Co...

However, evacuation orders remained in place for about 50,000 people in Garden Grove, California, located south of Los Angeles.