A $9.89 million mansion was destroyed by the fire in Orange County, and the homeowner watched it all happen on security cameras

• A wildfire in Orange County, California, has destroyed more than 20 homes in the past week.
• Among the destroyed homes was a $9.89 million mansion that was "one signature away" from being sold.
• Real-estate platform Realtor.com said it will start adding wildfire risk ratings to its listings.

A massive Orange County wildfire has burned down more than 20 homes in less than a week, including a $9.89 million Laguna Beach mansion that was "one signature away" from being sold, listing agent Leo Goldschwartz told The Orange County Register.

The unnamed homeowner, who was out of the country during the wildfire, watched through security cameras as the fire destroyed the 10,000-square-foot mansion, per The OC Register. The potential buyers had planned to renovate the property after their purchase, Goldschwartz told The OC Register. It is unclear what will happen next; Goldschwartz declined Insider's request for comment.

The mansion at 5 Vista Court, which had seven bedrooms and six full bathrooms, was listed for sale in January for $10.39 million before its price was dropped to $9.89 million in March, listing records show. It was located in Coronado Pointe, a gated hilltop community overlooking Laguna Beach in Laguna Niguel. 

The house had a two-level library and a pilates studio with a sauna and steam room, per the listing description. 

"It's a very special property. You cannot duplicate that home," Goldschwartz told The OC Register. 

Homes in Vista Court have a median listing price of $1.92 million, per real-estate platform Realtor.com, making the mansion at 5 Vista Court one of the pricier listings in the area.

While the mansion was insured, it has been getting more difficult and more expensive for California homeowners to insure their homes against wildfires due to increased risks from global warming, Goldschwartz told The OC Register.

The fire, which started on May 11, is 90% contained as of May 17, per The Orange County Fire Authority. In addition to the 20 homes that were completely burned down, 11 other houses in the area have sustained damage from the fire, per authorities.

Wildfires in California have become a more frequent occurrence in recent years due to extended periods of hot weather resulting from climate change. This fire is not the first to affect Orange County this year: In February, a 145-acre fire swept through Laguna Beach and Emerald Bay.

In response to growing wildfire threats, Realtor.com announced in a press statement plans to include a wildfire risk rating for all listings on its platform using data provided by First Street Foundation, a nonprofit organization that assesses climate risk, and the United States Department of Agriculture (USDA) Forest Service.

The risk rating is on a scale of one to ten and considers the property's exposure to fire risks, including the materials used to build the home and its proximity to vegetation.

"By integrating wildfire risk data directly into maps and property listings, we can help homebuyers feel confident when making one of the biggest purchases of their lives," Sara Brinton, Realtor.com's lead product manager, said in the press release.

Realtor.com and First Street Foundation did not immediately respond to Insider's requests for comment.