Investigators are working to determine what caused the one-alarm fire early Sunday morning in Hampstead that left one person dead and sent a 69-year-old man to the hospital, according to the Maryland State Fire Marshal.The blaze occurred around 1:29 a.m. Sunday in the 2600 block of Hoffman Mill Road.About 35 firefighters from several fire companies responded. The fire at the two-story, wood-framed single-family home was controlled within 30 minutes, but the structure is believed to be a complete loss, according to Senior Deputy State Fire Marshal Oliver Alkire.After flagging down a passing motorist who called 911, an occupant identified as 69-year-old Robert Schech was transported to Johns Hopkins Bayview Burn Center.He was treated and released, Alkire said. One occupant, who was not identified Sunday, died.Alkire said once inside the building, investigators determined the structural integrity was compromised. They contacted the Carroll County Advanced Technical Rescue Team to shore up the building before the investigation continued.As standard operating procedure, Alkire said an accelerant detection canine performed a scan of the building for any flammable liquids and worked in partnership with the area's primary law enforcement agency.The investigation is expected to continue Monday. A preliminary cause of the fire had not been released as of 7 p.m. Sunday.The State Fire Marshal's Office is investigating with help from the Carroll County Sheriff's Office. Anyone with information may call 1-800-492-7529.Sean Welsh of the Baltimore Sun contributed to this article. michel.elben@carrollcountytimes.com410-857-7873twitter.com/MichelElben