A mother bear in Katmai National Park, Alaska, was caught on camera having to rush to the aid of her cubs as they were swept down a waterfall. The three cubs seem to get caught in the current as they are taken over the short drop.

When the mother sees this happening, she rushes down to save her cubs. By the end of the video, she has fished the cubs out to safety, with explore.org, who help run the cameras, saying "thankfully they are all OK".

Cameras showing bears around Katmai National Park are being run by the US National Park Service in partnership with explore.org. They run a collection of round-the-clock live feeds of rivers where salmon are attempting their spawning migration and bears lie in wait to catch them as they leap upstream.

People are sharing and talking about the live stream using the hashtag #bearcam. Though the majority of salmon runs take place in the fall, a number also happen at other times in the year.