For too long now, Guy Webb and his family have worried about things that go boom in the night.
Almost weekly, small explosions erupt in the sky above the eastern part of the city, seemingly from somewhere around the dry Santa Clara River bed, not far from his Ventura home.
It's not quite the riddle of the Sphinx. But the ongoing cannonades are a worrisome mystery that police and residents like Webb fear could accidentally do more damage than simply fray some nerves.
The unexplained flash points come minutes apart, mostly on weeknights, always between 7 and 11 p.m. but concentrated between 8:30 and 9:30 p.m., accompanied by a bright flame that burns out in seconds.
They frighten Webb's children and send his dog into a tizzy; the walls and windows of his three-bedroom home shudder. Webb got stuck with a pricey vet bill after his dog hurt its leg jumping the backyard fence after one explosion.
"I don't know how close it is to our house, but the noise is loud enough that it scares them," said Webb, referring to his two young daughters. "It's alien to them and it's spooky."
Neighbors say the explosions have been lighting up the riverbed and nearby farmland for about six months. Witnesses report trails of yellowish orange incandescence lurching skyward, then loud booms popping off like fireworks.
They have alerted authorities, but Ventura police are at a loss to explain the booms or put a stop to them. Police have all but ruled out gunplay as a possible cause of the recurring blasts.
"It sounds sort of like fireworks," says James Dupree, who lives just down the street from the Ventura Police Department. "We hear them every three or four weeks, been hearing them for months."
"It sounds like a bomb to me," said William Meagher, who lives on Marmota Street. "Some of them are pretty big, and pretty loud.
"It seems kind of crazy that that loud of an explosion would be going on and nobody is able to find out where it's coming from."
Police investigators say the explosions have been going on for more than 20 years, the work of pranksters all too familiar with the combustible gases primarily used in the chemical welding trade.
They have concluded that the explosions are the product of gas-filled balloons, tied with a wick. Once released, the devices float skyward, erupting once the fuse has burned away.
But Ventura police still have no firm evidence, Lt. Carl Handy said.
"The problem is catching someone at it," Handy said. "It's difficult because by the time it detonates, it's several minutes after launch time and you can't always determine where it was set off."
Although the practical jokes--if that is what the explosions are--have been reported to police for years, they have yet to cause any serious injuries or property damage.
"We've had no residual fire problems as a result of these devices," Handy said. "But they're certainly unsafe."
Will Gary is a pump man at Air Liquide, a Ventura Avenue commercial welding supply store that sells a variety of flammable gases.
As one of the guys who fills empty tanks, he knows all about the balloon concoctions that some people set loose for kicks. Welders can fill a 100-cubic-foot tank for $15.
"Anybody can buy that stuff over the counter," he said. "It's an oxygen and acetylene mixture."
Gary said he has heard similar explosions over the Ventura River bed, short sharp blasts that seem to go off mostly on weeknights. But he said he does not know anyone who sets them off on purpose.
"At first I didn't know what it was--it's kind of like a muffled boom," said Gary, who acknowledged the noises could be the result of welding chemicals. "They're not really dangerous. They just go up in the air and explode, so there's nothing left."
Nonetheless, the sporadic explosions bother many east Ventura residents. And the lack of police action exacerbates their concern.
"I worry," said Valeri Ziegler, the mother of two young children, who has lived near Buena High School for more than six years.
"If somebody's out there popping a gun, where are these people and how close are they to my house?" she asked. "I don't want to have this stuff around my neighborhood. We don't have trouble around here."
Ziegler does not believe that the booms are the work of some mischievous welders working in the dry river bottoms after dark.
"We're too far away from the riverbed, so I don't think we could hear it from there," said Ziegler, who has to calm her 7-year-old daughter, Lindsay, when the explosions rock their home.
"By the time I go outside, I don't hear any more noises," she said. "So I just hold her and say it's OK until she falls asleep."
Dispatcher Sandy Butler is one of the people who answers the phone at the Ventura Police Department. Every time the culprit or culprits strike, she hears from distraught callers.
"I've heard about it for I don't know how long," she said. "Every once in a while we get a bunch of calls. They sound like they're scared--mostly because they don't know what it is."
Butler said she always dispatches an officer to the scene, but the investigators come up empty-handed.
"We respond every time, but by the time we get there it's not happening anymore," she said. "And when we investigate the next day, there's nothing left to find."
Despite the numerous complaints, police are not overly alarmed. They just worry about someone getting hurt.
"For some reason, in the last couple of years we've had more people reporting this kind of event," said Handy, the police lieutenant. "It sounds like fun, but someone's going to blow themselves up one of these days."