A 66-year-old Santa Rosa woman has died from injuries she suffered when an SUV turned into the path of her motorcycle near downtown's Third and Morgan streets, police said. Dawna Dianne Heller succumbed to her injuries on September 12, nearly two weeks after the crash, according to a Santa Rosa Police Department news release identifying her as the victim.
The collision happened the morning of August 30, just west of Santa Rosa Plaza, as reported by The Mercury News. Heller was riding a 2003 Harley-Davidson motorcycle north on the Highway 101 offramp when a driver in a 2020 Acura SUV, also traveling north on the offramp, turned left to head west and drove into her path, according to police. Officers and medical personnel arrived shortly after 10 a.m. to find Heller in critical condition; the Santa Rosa Fire Department and Sonoma County Fire District administered life-saving measures before she was transported to a local hospital.
SUV Driver Cooperated, Was Not Impaired
Santa Rosa police said in their release that the SUV driver was at fault in the crash and was not impaired at the time. The driver remained at the scene and cooperated with investigators, police said. Authorities shut down the intersection for two hours while officers worked the scene.
Under California Vehicle Code § 21801, a driver turning left at an intersection or offramp must yield to oncoming vehicles, including motorcycles, close enough to pose an immediate hazard, according to Sky Law Group. A related statute, California Vehicle Code § 22107, further requires that no driver turn or move from a direct course on a roadway until it can be done with reasonable safety, per the Shouse Law Group. Those statutes describe the legal framework for left turns and lane changes.
A Familiar Pattern in Fatal Motorcycle Crashes
The scenario described by police — a vehicle turning left across the path of an oncoming motorcycle — mirrors the most common cause of fatal multi-vehicle motorcycle crashes nationwide. National Highway Traffic Safety Administration data shows left-turning vehicles account for roughly 42% of such fatal collisions in the United States, according to San Jose Motorcycle Law, which notes drivers frequently fail to perceive oncoming motorcycles or misjudge their speed because of their smaller visual profile.
Sonoma County has recorded elevated motorcycle crash numbers in recent years. The county logged 137 motorcycle collision victims in 2023, ranking 17th among California's 58 counties for motorcycle crash injuries and fatalities, per California Office of Traffic Safety rankings cited by the Law Office of Michael Rehm. Separate state data shows the county recorded 160.3 motorcycle collisions per 100,000 residents in 2020, a rate cited by the Reiner, Slaughter & Frankel Law Offices as evidence that regional highways and urban connectors present heightened risk for riders.
Investigators Still Piecing Together Lane Positions
As of September 18, investigators were still working to determine which lanes the SUV and motorcycle occupied before impact, police said. The intersection is in downtown Santa Rosa; the AARoads page is included for reference. The crash occurred near a highway offramp.
The crash falls within a downtown zone where Santa Rosa officials have pushed traffic safety measures in recent years. In June 2023, the Santa Rosa City Council passed Resolution RES-2023-092 under California Assembly Bill 43, lowering speed limits to 20 or 25 mph across 15 downtown street segments, according to PublicCEO. Separate data reports 614 DUI arrests in 2025; impairment was ruled out in Heller's case.
Officer Handling Case Has Traffic Enforcement Record
The investigation is being led by Officer Carolina Zepeda of the department's traffic division. Zepeda was recognized at the Mothers Against Drunk Driving awards in July 2025 for outstanding traffic enforcement after recording 45 DUI arrests, one of several traffic officers honored as part of the department's ongoing safety push. Santa Rosa police traffic investigators are continuing their work on the case.
Police are asking anyone with information about the August 30 crash, including dash camera, surveillance, or cellphone footage, to contact Officer Zepeda at 707-543-8576. No further updates on lane positioning or potential charges had been released as of the department's September 18 announcement.
