Some more info (probably already well-known) on the story.
Shortly after SU-24 was downed two Russian SAR birds were launched to extract the pilots. These were Mi-8 helicopters, a toy helicopter comparatively to Mi-17 or Mi-24. One of the birds was seriously hit by the ground machine fire from ISIL or so called moderate opposition so it had to land; one of the SAR team onboard (a marine) was killed.
The second helicopter took all crew and SAR members from the first helicopter. The first helicopter was abandoned on ground. Soon it was destroyed with the US-made TOW rocket launcher by ISIL or so called moderate opposition (the video of this can be found on youtube).
So there are two casualties: the attack plane commander and a SAR marine.