DARRINGTON — As many as 18 people were hospitalized and later released Thursday after tear gas leaked from expended cartridges dumped in a Darrington garbage bin.

The tear gas belonged to the Snohomish County Sheriff’s Office, spokeswoman Rebecca Hover said. The cartridges were expired and had been emptied before they went into the trash.

Residual gas apparently leaked out after the trash can was moved.

That happened while the town’s garbage truck driver was making his rounds about 9:45 a.m., Darrington Mayor Joyce Jones said.

The sheriff’s office’s civil disturbance unit had stored tear gas in Darrington, Hover said. The gas isn’t lethal or permanently harmful.

Hazardous-materials teams from Everett and Marysville were called to the fire hall in Darrington and to Cascade Valley Hospital in Arlington, Snohomish County Fire District 24 spokeswoman Trudy LaDouceur said.

Within a half-hour, seven people were en route to the hospital in ambulances, Cascade Valley Hospital spokeswoman Kelly Penny said. Their symptoms included burning sensations to the eyes and mouth, tightness in their chests and other breathing problems.

The patients all were decontaminated and evaluated, Penny said. A total of 11 emergency crew members who came into contact with them went through the same process.

Everyone was in stable condition by 2 p.m., she said. They all were released a few hours later.

There was plenty of concern in the beginning, though.

“All hell is breaking loose up here,” Jones said at noon.

As the commotion died down, Jones said she was thankful for the quick thinking of the town’s emergency crews, many of whom are volunteers.

Darrington is known as a place where everyone volunteers and takes care of each other, she said. That shone through Thursday.

“They took care of the situation and made sure everybody was safe,” she said.

Among those taken to the hospital were the garbage truck driver and town public works crew members Rick Jones and Steve Wold, she said.

Darrington Ambulance Association members helped with the care of those taken to the hospital, LaDouceur said.

Town Hall, the library, the fire district office and the sheriff’s offices were closed to the public for some time after the leak.

Rikki King: 425-339-3449; rking@heraldnet.com.