Florida authorities are asking for the public's help in finding a missing 17-year-old boy out of St. Petersburg. A Florida Missing Child Alert was issued Friday for Allister Samer Nasr. According to the Florida Department of Law Enforcement, he was last seen leaving his home at 10 a.m. March 1 on Bayou Grande Boulevard NE. He is described to be 5-foot-9-inches with black hair and brown eyes. FDLE said he was last seen wearing blue shorts, a gray sweatshirt, white shoes and was riding a white beach cruiser bicycle. St. Pete police also say he is considered to be endangered. Anyone with more information about his whereabouts is asked to call FDLE at 1-888-356-4774 or the St. Petersburg Police Department at 727-893-7780.