She watched a wildfire destroy her town, so she's building fire-proof bunkers

"If it wasn't for Linda, we wouldn't have built this, I don't think," says Josh Behling, president of Wildfire Safety Systems and one of the inventors of the Fort.Fort is just one of several new businesses - from high-tech hydraulic homes to grass-clearing goats - to emerge as wildfires continue to worsen. On its website, NASA notes that extreme wildfire activity has doubled over the past two decades. Just this month, the Sandy Fire in California's Simi Valley, about 30 miles (48km) north-west of Los Angeles, sparked widespread evacuation orders and burned more than 2,000 acres.None of these solutions are cheap. On the low end, a herd of goats can cost upwards of $3,000 (£2,230) a day to clear a field. The Fort bunker starts at $60,000. Other companies offer flame-retardant home wraps and innovative sprinkler systems, which can cost thousands of dollars.The night before Fort's April launch, a pair of entrepreneurs appeared on US reality TV programme Shark Tank to pitch their own unique solution: HiberTec Homes, built on hydraulics that can disappear underground in minutes. The company said a 1,000 sq ft (93 sq m) home would cost approximately $1.2m.With a background in real estate and construction, Holden Forrest said he came up with the hydraulic-homes idea in 2019, right after the Woolsey fire, which wiped out 1,200 homes near his home in Malibu, also in California.He sketched an idea on the back of his nine-year-old daughter's homework, he says, and soon showed it to an architect, partly expecting him to "laugh me out of the room".