A methamphetamine lab was discovered Sept. 20 in a triplex at 6187 S. Sterne Parkway, Littleton. Three arrests were made.

Police arrived on scene after a witness reported a small “explosion” within the apartments. Police have had many calls to this location, and suspected drugs were involved, said Lt. Mike Broadhead, public information officer for the Littleton Police Department.

Officers attempted to make contact with the residents, but those inside locked the doors and windows and refused to exit.

“We had some concerns because of the nature of the type of call,” Broadhead said. “We didn’t feel we could just knock on the door.”

Littleton SWAT Team placed a chemical sensor into the apartment, which reacted positively to the presence of harmful chemical odors.

At this point, Broadhead said safety was the top concern, for those inside the unit and those living nearby. Nine different residences near the unit were evacuated, including 15-20 people.

Ronald Yoshida came out of the unit several hours after police arrived, where he was decontaminated by Littleton Fire Department, due to the possibility of chemical exposure.

Police suspected other people to be inside the apartment, and introduced a chemical irritant similar to pepper spray into the interior of the residence, which failed to bring the parties out. Ultimately, SWAT entered the apartment, wearing full chemical protective suits and arrested two individuals — 45-year-old Curtis Dale and a 28-year-old woman.

The scene was processed by agents from the South Metro Drug Task Force — a unit of officers from various jurisdictions throughout Arapahoe and Douglas counties. Methamphetamine was recovered, as well as a number of pre-cursor chemicals used in the manufacture of methamphetamines.

Yoshida and Dale were booked into Arapahoe County jail for possession and manufacturing of methamphetamine, a felony. The woman was arrested and cited for refusal to leave property upon request of a peace officer, a misdemeanor.

Most of the nearby residents were allowed back in their homes that day, but those in adjacent apartments are not expected to be allowed back in to their units until today, while police test for contamination.