An arrest has been made in connection with a suspected arson attack on a flat in Milford Haven.
A first floor flat at Chesnut Way, on the Mount Estate, was completely gutted by the fire that started around 1230 GMT on Tuesday.
No-one was injured in the fire but neighbours had to be evacuated.
Detective Sergeant Cameron Ritchie of Dyfed-Powys Police said: "It's only through good fortune that nobody was hurt or killed in this blaze.
"It was a significant fire that has extensively damaged one flat.
"If the emergency services hadn't have responded as quickly as they did the incident could have been much worse."
Anyone with information is asked to contact Haverfordwest CID on 101.