CARLSBAD–Two men were arrested Wednesday accused of manufacturing a controlled substance at their Carlsbad home, authorities say.

The residents, identified as 56-year-old Peter McDonald and 51-year-old David Silva, were booked into the Vista jail.

McDonald was charged with manufacturing a controlled substance, possession of a controlled substance for sale, and causing a structure fire. Silva was charged with manufacturing a controlled substance, and possession of a short barreled shotgun.

Just after 6:30 p.m., Carlsbad police officers responded to a structure fire in the 2000 block of Chestnut Avenue.

Witnesses reported seeing flames coming from the roof of the structure. When police and fire personnel arrived, the fire had already been extinguished by the residents. After ensuring they were not harmed, officers and firefighters noticed items commonly used to extract concentrated cannabis through the use of flammable solvents near the source of the fire. The product achieved through this type of solvent extraction process is often referred to as butane honey oil. Detectives found finished concentrated cannabis, over 50 marijuana plants, psilocybin mushrooms, a short barreled shotgun and additional items used in the production of concentrated cannabis through solvent extraction.