On July 1, 2022, four-year-old Quadrillion Ty Lee was killed by his mother, Molly Cheng (age 23), in a triple-murder suicide. Earlier that morning, the children's father, Yee Lee (age 27), died by suicide from a self-inflicted gunshot wound at the family's home in Maplewood, Minnesota, an event witnessed by Cheng. After police investigated the father's death, family members planned to take the children to their grandparents' house, but Cheng insisted they stay with her. Around 4 p.m., a relative called 911 reporting that Cheng intended to kill her children and herself. Police issued a statewide alert, but Cheng drove to Vadnais-Sucker Lake Park in Vadnais Heights, where she drowned and smothered Quadrillion and his three-year-old sister Estella, drowned his five-year-old brother Phoenix, and then drowned herself in Vadnais Lake. Quadrillion's body was recovered from the lake around 7:30 p.m. and he was declared dead. His death was ruled a homicide with the cause of death being drowning in fresh water.
Contexts/Conditions
Is there any mention of child drug ingestion or overdose?
Is there any mention of a drowning incident (either intentional or accidental)?
Drowning is the central cause of death. The vital records document (2022-MN-027585.pdf) states "Cause of Death: Drowning In Fresh Water." The People article states "Quadrillion and Estella died by drowning and smothering." The Safe Passage report states the mother "had drowned the children and then herself."
Is there any mention of a firearm incident?
While Quadrillion's death did not involve a firearm, the broader incident includes a firearm death. The People article states that the mother "reported that her 27-year-old husband Yee Lee had fatally shot himself in their Maplewood, Minnesota, home on July 1." The Star Tribune article similarly reports police responded "on the report of the suicide of an adult male." The father's firearm suicide was a precipitating event in the sequence that led to the children's deaths.
Is there any mention of inappropriate supervision (e.g., child wandered off and drowned)?
Is there any mention of inflicted injury? (e.g. slapped, punched, kicked, choked)
The People article states that "Quadrillion and Estella died by drowning and smothering." Smothering is an inflicted injury. The Safe Passage report classifies the abuse type as "Physical abuse" with the mother as the adult perpetrator.
Is there any mention of malnutrition, starvation, or dehydration?
Is there any mention of medical neglect?
Is there any mention of a motor vehicle crash or incident?
Is there any mention of a murder-suicide incident?
The People article explicitly states: "The sheriff is investigating the death of Cheng and her children as a triple-murder suicide." The Safe Passage report confirms: "she had drowned the children and then herself."
Is there any mention of outdoor elements (including hot car deaths)?
Is there any mention of prenatal substance exposure (including fetal alcohol syndrome or neonatal abstinence syndrome)?
Is there any mention of sexual abuse?
Is there any specific mention of shaken baby or abusive head trauma?
Is there any mention of prolonged abuse or torture (including restraints, captivity)?
Is there any mention of an unsafe sleeping environment?
Individuals Involved
Was an adoptive parent or guardian involved in the death?
Was a biological father involved in the death?
Was a biological mother involved in the death?
The Safe Passage report explicitly identifies the "Adult Perpetrator: Mother." The People article states "Molly Cheng smothered and drowned two of her children, then drowned the third child before ending her own life by drowning herself." She is identified as the children's mother throughout.
Was a day care worker, babysitter, or nanny involved in the death?
Was a female paramour or friend involved in the death (e.g., girlfriend, stepmother)?
Was a foster parent involved in the death?
Was a male paramour or friend involved in the death (e.g., boyfriend, stepfather)?
Was another adult relative involved in the death? (e.g., grandfather, aunt)
Was a sibling involved in the death?
Child Characteristics
Was the child adopted?
Was the child homeschooled (including "cyberschooling") or taken out of school?
Was the child in foster care at the time of the incident?
Was the child living with relatives at the time of the incident (but not parents)?
Is there any mention of a neurological developmental child disability? (e.g., autism, intellectual disability, nonverbal)
Is there any mention of a physical child disability? (e.g., feeding tube)
Is there any mention of prematurity or low birthweight?
Is there a history of child protection reports prior to death (for this child or siblings)?
Does the child have a history of foster care (but not in care at time of incident)?
Is there a history of a sibling death (separate incident from this death)?
Parent/Caregiver Factors
Was an adult charged or arrested for the child's death?
Is domestic violence by the parent/caregiver referenced?
Is there any mention that the death occurred in a temporary shelter or while homeless?
Is an intellectual disability of the parent/caregiver referenced?
Is the mental health of the parent/caregiver referenced?
The mother's mental health is clearly referenced. The Safe Passage report states: "family members notified police that she intended to harm herself and the children." The Star Tribune reports that authorities were searching for "a woman, reported to be suicidal." The People article states that a relative called 911 "stating that Molly was going to kill her children and herself." The mother ultimately died by suicide, confirming the mental health crisis.
Is a history of arrests or criminal charges for the parent/caregiver referenced?
Is substance use by the parent/caregiver referenced?
Notable Details
Several notable details emerge from the documents. First, the father Yee Lee (age 27) died by suicide (gunshot) earlier the same day, which the Safe Passage report states the mother witnessed: "On July 1, 2022, the children's father died by suicide, which his wife, the children's mother, witnessed." Second, family members attempted to intervene: after the father's death, the children "were going to go to their grandparent's house, but their mother insisted they stay with her." Third, despite a family member's 911 call at approximately 4 p.m. "stating that Molly was going to kill her children and herself" and a statewide alert being issued, the children's deaths were not prevented. Two siblings — Phoenix Lee (5) and Estella Zoo Siab Lee (3) — were also killed in the same incident.
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