Amid growing concerns about e-cigarette devices, a second death in America has been linked to vaping.

The death occurred in Oregon in July, the apparent result of a severe lung disease that health officials believe was caused by the use of a vaping device that contained marijuana. The victim’s name and age have not been released.

Officials at the Oregon Health Authority said the victim’s symptoms mirrored the respiratory problems seen in a growing number of vaping-related cases across the United States. More than 20 people throughout the midwestern U.S. were hospitalized last month due to breathing problems linked to vaping; in some of those cases, doctors originally diagnosed the patients with pneumonia. The symptoms of those affected by vaping have included shortness of breath, exhaustion, vomiting and weight loss, among others.

The news of the Oregon death comes after a person in Illinois died in late August due to a lung illness that was the result of an e-cigarette. The Oregon death is the first to be linked to a vaping device that contained marijuana, according to ABC News.

“We don’t yet know the exact cause of these illnesses – whether they’re caused by contaminants, ingredients in the liquid or something else, such as the device itself,” said Dr. Ann Thomas, the public health physician at the Oregon Health Authority, as quoted by ABC.

The death in Illinois last month marked the first such fatality to result from vaping, punctuating a summer filled with reports of hospitalizations and frightening episodes connected to e-cigarette devices. The victim was an adult who had developed a severe respiratory illness.

Vaping has skyrocketed in recent years, particularly among teens, as the devices have often been billed as a healthier alternative to conventional smoking methods. A survey from Gallup released in July found that cigarette smoking among Americans had dropped to an historic low, a decline that coincided with the steady rise of vaping.

But the medical community has urged extreme caution with the devices, stressing that vaping poses a number of its own unique risks.

“This tragic death in Illinois reinforces the serious risks associated with e-cigarette products,” Centers for Disease Control and Prevention director Robert R. Redfield said in a statement last month. “Vaping exposes users to many different substances for which we have little information about related harms – including flavorings, nicotine, cannabinoids, and solvents.”

Redfield said that the CDC is continuing to work with state and local governments “to learn the cause or causes of this ongoing outbreak,” underscoring that the risks associated with vaping are not yet fully understood. That has frustrated medical officials as they have treated patients suffering from illnesses linked to vaping.

The 22 midwesterners who were hospitalized this summer included several teens and individuals in their 20s, but doctors said they could not pinpoint the exact reasons for their illnesses. One such case involved a 26-year-old Wisconsin man whose lungs filled with fluid after using a vape cartridge he purchased off the street, prompting doctors to place him in a medically induced coma.