This is going to sound lacking in empathy, but you were lucky.
Why lucky? Well, at least the person was dead.

www.lancashiretelegraph.co.uk/news/4514369.Woman_leads_campaign_for_demolition_of_Nelson__suicide__car_park/?ref=rss

My friends mother was on the scene when a person jumped from that car park. The car park is quite high but when she had the misfortune to witness and then responded as a trained nurse. She was devastated to find that the person was not dead, in a great deal of pain. The person died within minutes, it was not good. Apparently, that is not the first person who did not die instantly from that height and the upside is that since it became known that instant death is not guaranteed there have been no further suicide attempts.
( d.r._and_quinch when will you be famous?, Sat 3 Aug 2013, 7:01, 1 reply)

They all come out of the woodwork
After it happened three separate work acquaintances told me they had seen something similar, One guy had somebody jump into a shallow river where he was running and take about 5 minutes to die in his arms while waiting for the ambulance.
(LangdaleBeck Langdale Beck, Sat 3 Aug 2013, 14:05, closed)