Days after mass evacuations were ordered in Orange County, the next few hours could be crucial in dealing with a volatile chemical tank at a Garden Grove aerospace company that has threatened to either explode or cause a major spill.

What to Know Evacuation orders remain in effect for about 50,000 people as firefighters worked to reduce the risk of a toxic chemical tank explosion at a Garden Grove aerospace facility. Some evacuation shelters were at capacity after authorities warned people of a possible toxic chemical spill or explosion of the overheating chemical tank at GKN Aerospace.