I was under the impression that paragliding was quite safe. Sure, hanging in the air by two carabiners from what is essentially a big kite might seem dangerous, but in reality it isn't too bad. Modern paragliders almost fly themselves. As with airplanes, it is take-off and landing that are most dangerous. Take-off isn't too bad, as I have seen students on a take-off run slip, fall down, and still take off. Weather, especially wind, plays a huge part in taking-off, but that is just planning ahead. The same as in any sport. One would not go golfing in a lightning storm.
It is possible to become unconscious in flight and the glider will still fly. In fact, most of the flying is performed without pilot input. Even if one eventually crashes into a tree it would not be catastrophic as the top speed for the basic glider is about 20kph(12.5mph). The dangerous part is landing as wind plays a big part here as well and stalling can be fatal. Flaring, which is the braking one does to slow down for landing, must be done at the correct time and with the correct pressure on the brake lines.
One rule while flaring is to never release the brakes once you start flaring. I have done this once and it causes one to gain altitude followed quickly by a steep decent. Luckily my mistake only caused a hard landing where I slid on my butt and opened the pouch for my reserve chute(See below for video). That was on my third flight solo.
My brother was not so lucky, He is in class and was doing well but on his third training flight yesterday flared way too high and hard. He came crashing down into the weeds in front of the instructors and other students. His foot really hurt, but as a man, he tried to walk it off and hoped that his foot was just sprained. Hours later when in his hotel room he decided it was serious and went to the clinic where it was found that his foot was broken in two spots. They also requested a CT scan as surgery might be needed which the result is unknown as I write this.
Today a female student in his class broke her ankle on landing. So perhaps paragliding is dangerous. Either my class was lucky, as we suffered no injuries even though there were multiple crashes, one of which included me being dragged across a field, or his class is very unlucky with somebody breaking a bone daily.