Tandem Insulin Pump Lawsuit Alleges Delivery Failure Led to 15-Year-Old Girl’s Death

Lawsuit claims insulin delivery failure caused the girl’s blood sugar to reach approximately 894 mg/dL, resulting in severe metabolic complications and anoxic brain injury.

A wrongful death lawsuit has been filed alleging that defects with a Tandem t:slim X2 insulin pump and its infusion set prevented a 15-year-old girl from receiving the insulin she needed to survive.

The complaint (PDF) was brought by Rachel Seal and Barry Seal, individually and as co-administrators of the estate of their daughter, Celeste Seal, in the U.S. District Court for the Southern District of California on September 18. It names Tandem Diabetes Care Inc., Unomedical A/S, Unomedical Devices S.A. de C.V. and Convatec Inc. as defendants.

The Seals claim the cannula in Celeste’s infusion set became bent or kinked, disrupting insulin delivery from her Tandem insulin pump without triggering an effective audible warning to alert her or her family.

Insulin Pump Problems

Insulin pumps are compact, battery-operated devices worn by people with diabetes to provide a continuous supply of insulin throughout the day. Many can also work with a continuous glucose monitor (CGM) to track glucose levels and deliver insulin through a small catheter inserted beneath the skin.

In recent months, several recalls have raised concerns about problems involving insulin pump devices from different manufacturers. Tandem issued a t:slim X2 insulin pump recall in August 2025 due to a speaker defect that could trigger error messages and interrupt insulin delivery. The problem was linked to at least 700 cases involving high blood sugar or other medical interventions, as well as 59 reported injuries.

The FDA also announced an Insulet Omnipod 5 insulin pump recall in March 2026 after identifying damaged internal components that could cause patients to receive too much or too little insulin. At the time, federal regulators had received at least 18 reports of serious injuries associated with the affected pods.

Tandem Insulin Pump Wrongful Death Allegations

According to the complaint, Celeste appeared to be functioning normally on September 1, 2024, with blood glucose readings in the low 100s. The pump recorded an empty-cartridge alarm at about 11 a.m., followed by an infusion-site change at approximately 4 p.m., after which the lawsuit says her glucose control began deteriorating.

At approximately 11:30 p.m., Celeste went to sleep after saying goodnight to her parents. The complaint alleges that sometime during the night her condition deteriorated severely, but no audible alarm communicated a life-threatening insulin-delivery problem to Celeste, her younger sister, who shared her bedroom, or her mother nearby.

By the early morning of September 2, Celeste was comatose. Her mother found her unresponsive at approximately 5:55 a.m., and Celeste suffered cardiac arrest while being transported to the hospital, requiring CPR before circulation was restored.

Hospital testing showed her glucose level was approximately 894 mg/dL, according to the complaint. She was admitted to the pediatric intensive care unit with severe metabolic complications, including diffuse anoxic brain injury caused by prolonged oxygen deprivation.

At about 6:18 p.m. that day, medical providers observed that the Teflon cannula was bent or kinked. Despite extensive treatment, Celeste never neurologically recovered and remained dependent on continuous insulin delivery before dying on September 20, 2024.

Celeste’s parents contend the t:slim X2’s safety systems should have recognized clinically significant insulin under-delivery and alerted the family soon enough to intervene.

“As the direct and proximate result of the acts and omissions alleged herein–including the California-based design, development, manufacture and/or assembly, testing, validation, warning, marketing, distribution, sale, safety, and post-market conduct described above–Celeste suffered severe metabolic decompensation and subsequently died on September 20, 2024.”

— Rachel Seal et al. v. Tandem Diabetes Care Inc. et al.

The complaint alleges Tandem failed to adequately design its occlusion-detection and alarm systems to identify partial or complete blockages quickly enough. It also claims feasible alternatives included improved occlusion-detection algorithms, sensors and alarm thresholds capable of detecting partial or complete occlusions within a clinically safe period.

Plaintiffs maintain that an effective warning could have allowed Celeste or her family to check her glucose and ketones, replace the infusion set, administer insulin through another method, contact her medical team or seek emergency treatment before the metabolic crisis became fatal.

The filing raises allegations of manufacturing and design defects, failure to warn, breach of express and implied warranties, wrongful death, survival damages and alleged violations of California consumer protection laws. It seeks compensatory damages associated with Celeste’s death as well as punitive damages and other relief.

Insulin Pump Lawsuits

Separate from allegations against Tandem Diabetes Care, personal injury lawyers are also investigating claims against Insulet, the manufacturer of Omnipod insulin pumps, which allege the company failed to adequately design and test its insulin pump pods or warn users about the risk of delivery failures.

Individuals who experienced serious health problems, including diabetic ketoacidosis (DKA), hyperosmolar hyperglycemic state (HHS) or diabetic coma after using an Omnipod 5 or another Insulet pod may have grounds for an Omnipod lawsuit.

Additionally, Abbott Laboratories faces dozens of lawsuits involving allegedly defective FreeStyle Libre 3 continuous glucose monitoring sensors, which have been shown to produce inaccurate glucose readings linked to more than 700 injuries and multiple deaths.

FreeStyle Libre 3 lawsuits are being investigated for individuals who may have suffered severe hypoglycemia, seizures, confusion, loss of consciousness, DKA or other acute metabolic emergencies allegedly caused by the defective CGM sensors.

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