Old film of a river rescue.

Long ago, on one of those EMT type tv series iirc, I saw a film where two (or three) boys were caught in an eddy in a fast flowing river and didn’t know how to get out. An old man jumped in and got the kids to safety one at a time, but exhausted himself doing so and drowned. He was totaled before he got to the last kid, but did it anyway.
Does anyone remember this?