This One Was Engine Failure:

An MQ-1B Predator that crashed Jan. 17 in Southwest Asia suffered engine failure stemming from a crack in the crankshaft, according to a summary of an Air Combat Command Accident Investigation Board report. The aircraft was destroyed upon impact. The crankshaft crack caused a connecting rod to fail, wedging itself in the opposing cylinder. A recent report indicates, though, that an increasing number of unmanned aerial vehicle crashes can be attributed to operator error.