The crunch of crashing cars, the sight of mangled metal - and the flashing lights that ensue - are part of living in downtown Alamo, less than 100 yards from the busy Danville Boulevard, he explained.
In that accident-prone area, across from Alamo Plaza, the sound was something he had almost grown accustomed to.
But this time a feeling in his gut pulled him away from his 5-year-old daughter and over to the bathroom window for a peek at what caused such a wrenching thud.
On that chilly November morning Cavalli was getting his kindergartener Tea ready for school in his Orchard Court home. And she was all set to go, minus one detail.
Her mother Tonya - who had left for a morning jog on the Iron Horse Trail - was to return and style Tea's hair for her. Try as he might, Cavelli could only do the basic ponytail. And that girl stuff was Tonya's territory.
But it was getting late. And Tonya still wasn't back.
Making his way outside, with the hope he would find Tonya stretching on the porch, Cavalli saw a woman running down his block.
"She screamed, 'Your wife's been hit!'" he remembered.
In the crosswalk in front of Alamo Plaza, at the intersection of Danville Boulevard and Orchard Court, Tonya had been struck by a truck going 35 miles per hour. She flew 38 feet and landed on the cold hard concrete just after 7:30 a.m. on Nov. 15.
As Cavalli frantically neared the scene, he caught a glimpse of his wife lying on her back in the middle of the street. The sounds of sirens were wailing in the distance.
"I'm thinking, 'Oh, my God, she's dead. What am I going to tell her mother?' And then I'm thinking, 'Who's gonna do Tea's hair every morning?'" a choked up Cavalli recalled.
An SUV had stopped at the crosswalk for Tonya, but as a truck approached, the driver assumed the SUV was turning right and pulled around it, slamming directly into her. The collision was so powerful her body left an 18-inch indentation in the vehicle.
"Her head was in a puddle of blood the size of this table," Cavalli said, nodding toward a round cafe table, outside Starbucks in Danville.
The exorbitant amount of blood came from head lacerations, caused upon impact. According to Cavalli there was so much of the thick red liquid, it was running toward the gutter. Car parts were strewn along the lanes of traffic, which had been blocked off by that time, during the morning commute.
"I dropped to my knees. The stupid thing to say is, 'Are you OK?' But that's what I said. She was semi-conscious. She could talk a little. She was in obvious pain," he said.
A doctor, who had witnessed the accident, was holding Tonya's head when Cavalli arrived and an Emergency Medical Technician was holding her hand. Alamo Sheriff's Department Cpl. Elmer Glasser, who was investigating a commercial burglary at Longs Drugs, came running, too.
"I took her hand and she said, 'I'm cold. I'm scared,'" Glasser said. "With her shaking and the amount of blood I knew it was very serious."
Cavalli was sure she was at least paralyzed.
"I was thinking, 'We can move. We can get one of those houses with the big doors,'" he said, imagining a life with Tonya in a wheelchair.
Tonya beats the odds
Flash forward three months and Tonya is recovering from a broken back, a concussion, several head lacerations and a massive hematoma on her hip - constant reminders of just how close she came to death.
Fortunately for her, the impact missed her spinal cord. She is fully able to walk and in recent weeks even jog again - slowly. She still suffers from vertigo, which she describes as "eternal bed spins" and she's working to get off her pain medication.
It wasn't until the Alamo Tree Lighting a couple weeks after the accident that Tonya spoke to Glasser and learned he had called the incident in as a fatality.
"It still doesn't make sense in my head that I'm alive," she said last week.
For the Alamo mother and business woman, the story has a happy ending - but not entirely.
She still worries that Alamo's most critical safety issue hasn't been solved. And she fears the next person hit won't be as fortunate.
"Somebody is going to die in that intersection," she said.
Time Bomb Boulevard?
The issue of traffic safety on Danville Boulevard in Alamo is nothing new. It's as longstanding as it is controversial. But Tonya's story adds another chapter.
In front of Alamo Plaza, where traffic lanes narrow from four to two, with a center lane for left-hand turns, there are 14 driveways and two streets in a span of about 1,200 feet. They belong to gas stations, shopping center parking lots and small streets. And residents say, with all that pulling in and out, it's an accident waiting to happen.
The stretch is used as a commuter shortcut from the jam-packed I-680 during rush hour in the unincorporated area, which relies on the California Highway Patrol for traffic violations. In front of Alamo Plaza, shoppers and neighbors say they're scared to cross the street.
"They fly through there," Cavalli said. "There's just so much of this going on."
Over the years, community groups have suggested a roundabout, a stop light, flashing lights, stop signs and speed limit reduction. Others make jokes about putting gates at the borders of Alamo and only letting the locals through.
Overall, though, residents have been split on the issue. Some folks feel a stoplight would both take away from the area's rural character and clog the major downtown artery, while others see it as a serious safety concern - worth an unattractive light.
"We've always said it's gonna take someone getting killed to get this attention. We just never thought it could be us," Cavalli said.
The county comments
Director of County Public Works Maurice Shiu said the Danville Boulevard project has been going on "longer than you or I would like to think" and that part of what makes the process slow is that "there are a lot of opinions" in Alamo.
"We are trying to navigate safety needs and respect the vision for the community. It's not easy, you have a lot of people looking at the subject from different angles," he said.
After County Public Works found a roundabout was not realistic financially, "phase one" of the boulevard project began. This meant adding lights to a crosswalk at Jackson Way, one street north of where Tonya was hit, and putting in an additional turn lane onto Stone Valley Boulevard.
In general, Public Works takes into account areas it considers hazardous and acts quickly - by putting in signs or speed bumps - in those places, Shiu said. But Danville Boulevard hasn't proved to be hazardous in the eyes of the county, he said.
"It's important but it's not an emergency. Yes, we have an unfortunate accident. But at this point we are not going to take any drastic action," he said.
According to District 3 Supervisor Mary N. Piepho, the county has also asked California Highway Patrol for increased enforcement on Danville Boulevard, although it has not requested any specific amount.
"It's what they can do in their regular schedule," Piepho said of CHP enforcement. "We've never had a problem. They have always been very responsive."
Is CHP the answer?
But Tonya is not convinced.
"There's a big freeway next to us, I don't think it's realistic that they're gonna patrol our area," she said.
Scott Yox, spokesman for the Contra Costa branch of the CHP, said an officer is "out there almost on a daily basis," generally in the morning. He said they are aware of the problem and that they enforce traffic violations in Alamo "when they've got a free opportunity."
Cpl. Glasser said the Valley Station is taking on some of the traffic violation issues using radar enforcement during commute hours. Officially, though, it's the responsibility of the CHP.
Additionally, Piepho said brighter lights will be added in the Jackson Way crosswalk and there's currently an effort to reduce the speed limit from 30 miles per hour on that section of Danville Boulevard.
"We are working with the local community to reduce speed essentially in the downtown area ... We are working hard and hopefully making an impact," Piepho said.
Still, Tonya says they feel underrepresented and ignored. Lowering the speed limit does no good if there's no one there to enforce it, she said.
"There's no skin in the game. There's nobody representing us. This is a basic example," she said.
Ultimately, the only time she feels angry about the accident is when she thinks about how her daughter almost had to go through life without a mom. She wants people to know how much damage a car can do - even one that's going 35 miles per hour.
And she feels compelled to get the word out about the danger of the intersection, just yards from her home.
"I'm the kind of person who believes there are no accidents. Everything happens for a reason," she said. "Maybe I'm supposed to solve this problem."
As luck would have it, Tea still has a mommy to braid her hair in the morning. It's just that the next family - or the next little girl - might not be so lucky, she said.