Just to add...
Nomex underclothing (long-sleeve vests, leggings and socks etc) are available from the likes of Sparco, OMP and Alpinestars etc. Some folk may find that this could offer them useful protection when worn under appropriate cotton clothing if they don't want to wear a full external suit?
This is a very sad accident and took me straight back to a fatal accident (1997) up the coast from where I live at the now disused Brunton Airfield in Northumberland. A Maule crashed, caught fire and the eyewitness accounts that appeared in the news made for awful reading.