SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/citizenship> <http://dbpedia.org/resource/United_States> . ?x <http://dbpedia.org/ontology/deathCause> ?uri . }
What have some US citizens died of?
SELECT DISTINCT ?k WHERE { ?m property:death_cause ?k . . ?m property:citizenship resource:United_States }
answer
The death cause of the people from United States are [answer].
The cause of death for the US nationals has not been released.