Devon and Cornwall Police has confirmed that a woman and her elderly parents have died of suspected carbon monoxide poisoning at a caravan park in Camborne.
Officers say the alarm was raised at just before 1pm after the couple's helper was unable to reach them.
Firefighters visited the static caravan at Tremarle Home Park and recovered the bodies of three people and a dog from inside.
More top news
The popular game relies on Google Maps, a problem in South Korea as those functions are limited by the government.
A Met Office warning covering much of England and south-east Wales is expected to remain in place until 11am.
A band of cloud and patchy rain is expected across Scotland and Northern Ireland, moving southeast as the day progresses.