North Wales Fire and Rescue say a body was found at a terraced house in Ffordd Llanllyfni, Penygroes, when they arrived to tackle a blaze on Tuesday afternoon.
The body was discovered in the kitchen at around 3pm by fire crews from Caernarfon. More details are expected later.
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Early cloud and rain will spread westwards across all parts. However, it will become drier with brighter spells developing.
Any showers will ease through the evening to leave a mainly dry night with clear spells and light winds.
A coroner says that the family of a 15-year-old girl, who died after falling from a bridge, was let down by health authorities.