News & Analysis
July 13, 2026
A daughter is one step closer to putting Big Oil on trial for their role in the heat wave that killed her mother after a Washington judge rejected the companies’ attempts to have her first-of-its-kind case dismissed last week. The case will now proceed toward discovery and trial.
Misti Leon sued ExxonMobil, BP, Chevron, Shell, and other oil and gas companies for fueling the extreme heat that killed her mother, Julie Leon, on the hottest day in Washington State history during the 2021 Pacific Northwest heat dome. Scientists found that the event would have been “virtually impossible” without climate change.
The temperature rose above 100 degrees for the third consecutive day on June 28, 2021, when Julie was driving home from a doctor’s appointment in Seattle, Washington. Julie was later found unresponsive in her car with the windows down, parked along her route home — and despite several rounds of life-saving measures, she could not be revived. The medical examiner ruled Julie’s cause of death as hyperthermia — a condition that killed hundreds of people during the heat dome.
Judge Matthew Lapin denied the companies’ joint motions to dismiss and strike the case. Judge Lapin clearly rejected the oil companies’ arguments that Leon’s lawsuit was preempted by federal law because it was an attempt to regulate the companies’ emissions — an argument Big Oil companies often make against the vast array of climate-related lawsuits they are facing from dozens of communities across the country.
“These state-law claims are not pre-empted or precluded by federal law nor are they preempted by the Clean Air Act,” Judge Lapin wrote. “This is so because these claims are not about regulating emissions.”
The court granted ConocoPhillips’s request to be removed from the case, but allowed Ms. Leon the opportunity to amend her complaint. Olympic Pipeline Company was removed as a defendant in the case.
Timothy Bechtold, an attorney representing Misti Leon, told Law360 that the family is "glad that the court was not persuaded by the defendants' grab bag of arguments to stop the case from moving forward to a decision on the merits."
"These rulings allow the Leon family to continue their pursuit of justice for their loss," Bechtold told Law360.
