CALL NOW
Fatal Crash April 2, 2023 Treat Boulevard and Alderwood Road, Walnut Creek, CA

Fatal Crash in Walnut Creek Near Highway 680 Killed Concord Man

CHP said a Honda Accord lost control just before dawn and struck both a stopped Nissan van and the man standing behind it at Treat Boulevard and Alderwood Road near Interstate 680. Follow-up reporting later identified the man killed at the scene as 34-year-old Sergio Quilici of Concord.

Incident Summary

Type
Two-vehicle collision involving a pedestrian outside a stopped vehicle
Location
Treat Boulevard at Alderwood Road, near I-680 in Walnut Creek
Date
April 2, 2023
Time
About 5:42 a.m.
Victim
Sergio Quilici, 34, of Concord
Fatality
One person was pronounced dead at the scene
Injured Driver
Honda Accord driver suffered major injuries
Vehicles
Nissan van and Honda Accord
Reported Sequence
CHP said the Honda lost control and struck the stopped Nissan and its driver, who was standing behind the van
Investigation
CHP Contra Costa investigated and asked witnesses to contact its Martinez office
Public Follow-Up
Reviewed public coverage identified the victim, but did not report DUI findings, speed findings, or filed charges

What CHP Said Happened at Treat and Alderwood

According to CHP Contra Costa, the crash happened at about 5:42 a.m. on Sunday, April 2, 2023, at Treat Boulevard and Alderwood Road in Walnut Creek. Investigators said a Nissan van with one occupant was stopped facing westbound on Alderwood at Treat. The driver had exited the van and was standing behind it when a westbound Honda Accord approached the intersection.

CHP’s preliminary account said the Honda driver lost control and struck both the Nissan and the man standing behind it. The Nissan driver was pronounced dead at the scene. The Honda driver was taken to a hospital with major injuries. Early reporting described the incident as a two-vehicle crash, but the follow-up details make clear the fatal victim was outside his stopped vehicle when he was hit.

Follow-Up Reporting Identified the Man Killed

Later coverage from local outlets and the Contra Costa Coroner’s Office identified the victim as Sergio Quilici, a 34-year-old man from Concord. One report noted that an earlier spelling of his surname had been corrected after a family friend and the coroner’s office confirmed the proper spelling. That kind of correction matters in legacy crash pages, because identity errors can linger online long after a family is already dealing with the loss.

The same follow-up reporting repeated CHP’s position that Quilici had stopped his Nissan van, stepped out, and was standing behind it when the Honda struck him. Public reporting reviewed for this rebuild did not add any official finding that alcohol, drugs, or excessive speed caused the collision, and it did not report any criminal charges tied to the crash.

Why the Pedestrian Detail Changes the Legal Picture

This was not just a crash between two moving vehicles. Based on CHP’s public account, the fatal victim had already exited his van and was outside it when he was struck. That can change how a case is analyzed, because investigators and civil attorneys may need to examine roadway design, visibility, lighting at daybreak, approach speed, control loss, impact angles, and whether there was enough time or distance to avoid the collision.

When a person is killed outside a disabled or stopped vehicle, surviving family members may have questions that a short initial news brief never answers. A wrongful death lawyer or pedestrian accident lawyer may look at scene evidence, vehicle damage, witness statements, surveillance footage, and crash reconstruction to understand whether negligence caused the death.

What Families Often Need After a Fatal Walnut Creek Crash

In a fatal case like this, the first police summary is only the starting point. Families often need to know whether the investigating agency reached a final conclusion, whether additional evidence surfaced after the initial press release, and whether insurance issues or third-party liability may affect a civil claim. Even when public reporting remains limited, preserving the known facts early can matter.

Context From the Public Record

5:42 a.m.
CHP said the collision happened shortly before sunrise, when visibility and reaction time can become key issues in a crash analysis.
CHP Contra Costa preliminary report as quoted by local outlets
1 Fatality
Sergio Quilici was pronounced dead at the scene after being struck while standing behind his stopped Nissan van.
Contra Costa Herald and DanvilleSanRamon.com follow-up reporting
No Public DUI or Charge Finding Reported
The reviewed public follow-up coverage identified the victim and repeated CHP’s loss-of-control sequence, but did not report an official DUI finding, a speed determination, or filed criminal charges against the injured Honda driver.
Reviewed local follow-up coverage through April 7, 2023

Frequently Asked Questions

Who was killed in the Walnut Creek crash near Highway 680?
Follow-up reporting said the victim was Sergio Quilici, a 34-year-old man from Concord. He was pronounced dead at the scene after CHP said a Honda struck him while he was standing behind his stopped Nissan van.
Was the victim inside his vehicle when the crash happened?
No. CHP’s public account said the Nissan driver had exited the van and was standing behind it when the Honda Accord lost control and hit both him and the vehicle.
Did public reporting say the Walnut Creek crash involved DUI or speeding?
Not in the follow-up sources reviewed for this rebuild. Those reports said the Honda driver lost control, but they did not publish a confirmed DUI finding, a final speed finding, or criminal charges.
What kind of legal claim can arise after a fatal crash like this?
Depending on the facts, surviving family members may have a wrongful death claim. That kind of case can focus on who caused the collision and the economic and personal losses suffered by the family.

Fatal crash cases usually get clearer after the first headline, not before.

If your family lost someone in a Walnut Creek collision, Scranton Law Firm can help investigate the known facts, preserve evidence, and evaluate whether a wrongful death claim may be available.

Free Case Evaluation

100% Confidential · No fees unless we win