Oregon’s record-breaking heat wave reached a death toll of 107 on Tuesday, according to officials.

The victims range in age from 37 to 97, according to the Oregon State Medical Examiner, as the state has been reeling from scorching triple-digit temperatures from June 25 to June 30.

So far, 67 deaths — more than half the state’s heat wave-related deaths — were reported in Multnomah County, prompting the county to call it a “mass casualty event.”

Multnomah County health officials said in a news release the suspected cause of all the deaths is hyperthermia — the condition of having a body temperature well above normal. So far, 40 have been formally ruled hyperthermia deaths, and the rest are yet to be officially ruled.

The county’s victims ranged in age from 44 to 97.

Some of the dead were found inside their homes without air conditioning or fans, according to local ABC affiliate KATU. Portland recorded a high of 116 on Monday, June 28.

One of the victims was Guatemalan immigrant Sebastian Francisco Perez, 38, who came to the U.S. on May 5 to work on a farm in rural St. Paul, according to Oregon Live. He died June 26 while working at a tree farm in the extreme heat. Three vigils were held for him in St. Paul on Saturday, the outlet reported.

In response to natural disaster, Multnomah County Chair Deborah Kafoury said the county opened three 24-hour cooling centers, nine cooling spaces, directly contacted tens of thousands of seniors, people with disabilities and pregnant women and deployed more than 60 outreach teams to focus on people without housing or shelter in the heat wave.

Washington County reported nine deaths, Clackamas County 11, Marion 13, Deschutes two, Linn two, and Columbia, Pole and Umatilla counties all reported one death from the heat.

An excessive heat warning was in effect the weekend of the wave from the National Weather Service, and the weekend set records for hottest days in history in multiple cities.

Gov. Kate Brown called the heat wave’s death toll “absolutely unacceptable” and said that despite preparation efforts across the state, “we still lost too many lives,” during an appearance on CBS’ “Face the Nation.”