Firefighting commanders from a dozen agencies throughout the East Bay huddled in the chilly fog at the top of the Oakland hills Tuesday to deliver a sober, and increasingly familiar, message about the approaching fire season: Get ready, because trouble is on the way.

Coming off California’s most destructive fire season ever, with the Wine Country blazes alone killing 41 people, tensions were already high heading into the summer. But as they stood at the edge of one of last year’s biggest blazes in the East Bay’s fire-prone slopes, even the most hardened of the firefighters looked a little worried as they surveyed the lush overgrowth all around them.

“Somewhere, sometime, someone is going to do something stupid, and things are going to light up,” said Vince Crudele, who leads the Oakland Fire Department’s vegetation management unit. “That’s just the way it is, and it gets more serious every year.”

The command gathering — staged to ask for the public’s support in cutting down vegetation around houses — was held on Grizzly Peak Boulevard near South Park Drive, where a 20-acre blaze in steep terrain required 14 agencies to squelch in August. The only remnants were faintly blackened debris, but as Crudele waved a hand at the thick eucalyptus and truck-high brush spreading off in each direction, he shook his head.

“Look, we’ve got 23,000 homes in these hills in high danger area, and I just ran out of money for clearing vegetation,” Crudele said. He added that in 2013, the year voters rejected continuation of a decade-long $65 parcel tax to pay for wildfire prevention, his crews were able to clear 121 miles of roadway of dangerous brush and trees. But resources dwindled after the tax expired in 2014, and last year’s road-clearance total was just 71 miles.

“And that’s just what I’m able to clear,” he said. “There are 16.5 square miles of area to cover up here just in the hills, with 307 miles of roadway. How can anyone manage all of that?

“And look over there at the end of this lot, and there are 100 cigarette butts on the ground,” he said. “Sometime, someone is going to run a hot mower across their yard up here, someone’s going to blow off illegal fireworks — you name it. If we’re going to prevent as many fires and save as many lives as we possibly can, we need people to step up and help.

“It’s that plain and simple.”

That means homeowners have to clear 100 feet of defensible space around each house, cutting down flammable brush in each yard, make sure their roofs are fire-resistant — all the kinds of things fire managers advise every year. But, Crudele and his colleagues said Tuesday, the advice is more important than ever as each year the fire season gets more serious — driven by drought, climate change and an ever-increasing population living closer to woodlands.

After the 1991 East Bay hills fire flattened 3,276 homes and killed 25 people, residents were pretty careful about keeping their properties safe, said Oakland Fire Chief Darin White. But those efforts slipped as the years went by, huge homes replaced the bungalows that burned and people fell back in love with leafy, attractive trees around those new homes.

“A lot of people living here in the 1980s and early 1990s have either moved away or passed on, and we have a lot of new residents who don’t really realize the danger up here,” White said. “We need them to work with us on their vegetation management, keep vigilant.

“And that means all year round now, not just during what we used to consider fire season in the summer and fall,” he said.

Jonathan Cox, battalion chief with the state Department of Forestry and Fire Protection, said that preparation has to extend to preparing go-bags with medications, identification and clothing in the event of evacuation.

“People have to take this seriously and leave immediately when fire officials tell them to evacuate,” he said. “Because, like we saw in the North Bay in October (with the Wine Country fires), when you have to move, you have to move fast.”

He said ominous signs for the coming season are already in the numbers. So far in 2018, 1,283 fires have burned throughout the state — and at this time in 2017, there had been just 1,049.

Berkeley Assistant Fire Chief Keith May pointed out that on average, a major wildland-urban interface fire erupts in the East Bay — like the one in the hills in 1991 — every 25 years or so.

“We’re due,” he said. “I don’t know that these hills are more likely to ignite than anywhere else that has this kind of wildland interface (houses laced right up near forestlands), but they are definitely ready to go.

‘It’s thick with brush and trees and eucalyptus. All it takes is one spark.”

Kevin Fagan is a San Francisco Chronicle staff writer. Email: kfagan@sfchronicle.com Twitter: @KevinChron