Thanks for the link to the FAA test. I picked up one conclusion that made reading the whole thing worthwhile, even though I am not an Electrical Engineer and do not claim to understand the report completely:

"In general, of all of the lithium-ion cells that were tested, LiFePO4 would be considered the safest cathode material because of the relatively low temperature rise and the resulting low likelihood for thermal runaway to propagate. LiCoO2 and LiMnNi would be considered the most hazardous because of the relatively large temperature rise and high probability for propagation of thermal runaway to adjacent battery cells."

Once again, thanks for the link.