Atria Senior Living Lawsuits Over Fatal Poisoning Incidents

Three residents at two Atria Senior Living facilities in the San Francisco Bay Area died in August 2022 after ingesting cleaning chemicals, and the Atria Senior Living poisoning lawsuits that followed have produced wrongful death claims by both families, a published California appellate ruling on arbitration, a felony elder abuse conviction against one employee, state license revocation actions, and the eventual closure of the San Mateo facility.

What Happened at the Two Facilities

The two incidents occurred four days apart at separate Atria communities.

On August 23, 2022, Constantine Albert Canoun, a 94-year-old resident with dementia in the memory care unit at Atria Walnut Creek, wandered into the facility’s kitchen and drank an all-purpose liquid cleaning agent. The kitchen door had been left unlocked and cleaning supplies were stored on a shelf beneath the counter within reach. Canoun died on August 31, 2022. The coroner attributed his death to “caustic injury to pharynx, esophagus and stomach, due to ingestion of liquid cleaning agent.” A state investigation later found that the facility had failed to maintain the constant supervision required for residents in its memory care unit.¹

According to a lawsuit referenced in reporting by the East Bay Times, Atria initially told Canoun’s family that his internal injuries were caused by eating “spicy chips,” an account the family’s attorneys called a lie meant to deflect liability.²

On August 27, 2022, at Atria Park of San Mateo, at least three staff members transferred an industrial-strength dishwasher cleaning fluid from a five-gallon container into an unmarked beverage pitcher. A fourth employee, unaware of what was inside, served the liquid to three residents with dementia, believing it was fruit juice. State regulators found that none of the employees involved had been trained on the proper handling or transfer of chemicals in the kitchen.³

Trudy Maxwell, 93, died on August 29, 2022. Her family’s attorneys said the cleaner “essentially melted” her mouth, throat, and esophagus.⁴ Peter Schroder Jr., also 93, died on September 7, 2022, after being intubated for acute respiratory distress. A third resident, Richard Fong, survived with burns to his lips, mouth, and tongue.⁵

The Wrongful Death Lawsuits

Both families sued in San Mateo County Superior Court within weeks of the incidents, and both complaints framed the deaths as the product of cost-cutting on staffing and training rather than isolated mistakes.

On September 29, 2022, the eight surviving children of Trudy Maxwell filed suit against Atria Management Company, Atria Park of San Mateo, Atria Senior Living, facility operator WG Hillsdale SH LP, and community director Jennifer Duenas. The complaint alleged wrongful death, negligence, and violations of California’s Elder Abuse and Dependent Adult Civil Protection Act, and said Atria’s staffing and training decisions were “part of their scheme to profit from vulnerable adults.”⁶

Susan Schroder, Peter Schroder’s daughter, filed a separate suit on September 16, 2022, naming Atria Park of San Mateo, Atria Senior Living, Duenas, and regional vice president Kris Waluszko. It alleged elder abuse, negligence, and wrongful death, and pointed to security footage showing an employee transferring the cleaning solution to an unlabeled container and leaving it on a kitchen counter after being called away to handle a “disruption” caused by short staffing.⁶ The Schroder complaint also raised the Walnut Creek death and alleged that Atria “did nothing” to warn staff at other facilities after Canoun died.² Atria maintained that the two incidents were “isolated and unrelated” and that the San Mateo poisoning violated the company’s existing internal policies.⁵

The Arbitration Ruling in the Maxwell Case

The Maxwell suit produced a notable appellate decision. Atria moved to send the dispute to private arbitration, relying on an agreement signed by James Maxwell III when his mother moved in. The trial court denied the motion, finding that the son could not bind his mother because he did not hold her healthcare power of attorney. In September 2024, California’s First District Court of Appeal reversed and sent that piece back for reconsideration under the California Supreme Court’s decision in Harrod v. Country Oaks Partners, LLC, which held that signing an optional arbitration agreement is not a “healthcare decision.”⁷

The appellate court also affirmed two points that matter to the family. The children’s individual wrongful death claims cannot be forced into arbitration because they were never parties to the agreement and their claims are independent and personal under California law. And California’s rule allowing a judge to refuse arbitration when parallel litigation risks conflicting rulings was not preempted by the Federal Arbitration Act in this case, because the arbitration agreement itself permitted California procedural rules.⁷

Criminal Charges Against the Employees

In April 2023, the San Mateo County District Attorney charged Alisia Rivera Mendoza, the employee who poured the cleaning fluid into the pitcher, with two counts of involuntary manslaughter and three counts of elder abuse. She faced up to eight years in state prison.⁸

On the morning her trial was set to begin, Mendoza accepted a plea deal. She pleaded no contest to one count of felony elder abuse, and the involuntary manslaughter counts were dropped. On November 21, 2025, San Mateo County Superior Court Judge Michael Wendler sentenced her to 40 days in county jail with no credit for time served, 350 hours of community service, and two years of supervised probation. She was permanently banned from working in nursing homes or care facilities and ordered to report to jail on February 7, 2026. Part of her community service requires her to speak to senior care workers about the consequences of her actions.⁹¹⁰

In the Walnut Creek case, the Contra Costa County District Attorney charged Atria employee Lateshia Sherise Starling in January 2023 with one count of felony elder abuse resulting in death in connection with Canoun’s poisoning.¹ The available record does not show a final outcome in her case.

Both cases were referred to California Attorney General Rob Bonta to decide whether criminal charges should be filed against Atria Senior Living as a corporation. As of February 2023, the office was reviewing the matter.¹¹ No corporate criminal charges appear in the available record.

State License Actions and the San Mateo Closure

The California Department of Social Services moved against both facilities. On March 14, 2023, the state fined Atria Park of San Mateo $39,500 and filed to revoke its license.³ On April 27, 2023, the department filed a separate action to revoke the license of Atria Walnut Creek.¹ Atria contested both, and both facilities remained open during the proceedings.

Atria Park of San Mateo is now closed. The California Department of Social Services lists the closure as “Licensee Initiated,” effective January 6, 2026.¹² The available record does not include a final resolution of the Walnut Creek license case.

Prior Complaints at Both Facilities

Both families’ attorneys pointed to a history of prior complaints. ABC7 reported that the Walnut Creek facility had at least six complaints investigated by the state since 2018, with past citations for failing to provide adequate staffing and for a resident sustaining an injury while in care.¹³ The San Mateo facility had 12 prior complaints alleging staff negligence before the poisoning.⁵

1
NBC Bay Area. Atria Walnut Creek License Revocation
2
East Bay Times. Man Who Died in Walnut Creek Senior Care Facility Accidentally Drank Poisonous Substance
3
NBC Bay Area. California Social Services Atria Park San Mateo
4
Washington Post. Senior Facility Juice Cleaner Poisoning
5
ABC7 News. Atria Park San Mateo Cleaning Solution Senior Death
6
McKnight’s Senior Living. Poisoning Death Lawsuits Renew Interest in Assisted Living Staffing Regulations
7
FindLaw. Maxwell v. Atria Management Company LLC
8
San Mateo Daily Journal. San Mateo Atria Worker Charged With Involuntary Manslaughter
9
KRON4. San Mateo Elderly Care Facility Worker Sentenced for Toxic Juice That Killed Two
10
Patch. Residents Poisoned SMC Retirement Home Killing 2 Woman Sentenced 40
11
NBC Bay Area. Atria Poisoning Deaths
12
California Department of Social Services. Facility Detail – Atria Park of San Mateo
13
ABC7 News. Atria Senior Living Walnut Creek Poisoned Second Death