A dangerous chemical leak that forced nearly 50,000 people from their homes in Orange County, California, may have taken a hopeful turn after crews discovered what officials described as a pressure-relieving crack in the leaking industrial tank.

Crews are continuing to monitor the Garden Grove area amid the chemical incident that has prompted mass evacuations, a state of emergency and a class-action lawsuit. The whole ordeal began around 3:30 p.

Evacuation orders were issued to 40,000 Orange County residents. A fire official said a major spill or an explosion were the only expected outcomes.