A Silver Alert has been issued for a missing 16-year-old girl in Danbury.  Heidi Logan-Sorenson was reported missing on August 19th. State police say Logan-Sorenson may have shaved her head, and may respond to the name 'Lee' or 'Logan'.  She was last seen wearing a hat or gray-colored hoodie and black-colored jeans.  Logan-Sorenson is 5-foot-2, weighing about 110 pounds and has blue eyes.  State Police also issued a Silver Alert for another 16-year old girl missing from Danbury since Monday.  Kaylee Avila was last seen wearing a grey hooded sweatshirt, pink sweatpants and flip flops.  She had a Henna style design on her right hand and blond tips on black hair.  Anyone with information is asked to call Danbury police at 203-797-4614