A man and a woman have been arrested on suspicion of murder following the "unexplained" death of a 13-month-old girl.
Police were called to reports that the baby had been found unresponsive at an address in Marton Drive, Blackpool, at about 8am on Friday.
Emergency services attended but the child was pronounced dead at the scene.
A spokeswoman for Lancashire Police said: "The death is currently being treated as unexplained and an investigation is under way. A post-mortem examination will be carried out to try to establish the cause of death.
"Two people, a man aged 21 and a woman aged 24, have been arrested on suspicion of murder and are currently in custody.
"Inquiries are ongoing."