Irvine has had several wildfires in recent memory, and we should expect more. On a red flag day, if you live within 3-5 miles of any mountain/wilderness zone, your home is at risk of burning down.
The recent fires have proven that nothing is really safe. The local government was ill-prepared for the ferocity and speed of these events. Thousands of structures/homes were lost, fire hydrants ran dry, and scores of people were killed/missing. This easily could have been an OC fire with similar results.