The cease-fire ended abruptly on 6April 1994 when President Habyarimana's plane was shot down near Kigali Airport, killing both Habyarimana and the new President of Burundi, Cyprien Ntaryamira. The pair were returning home from a regional summit in Dar es Salaam at which the leaders of Kenya, Uganda, and Tanzania, had urged Habyarimana to stop delaying the implementation of the Arusha accords. The attackers remain unknown. Prunier, in his book written shortly after the incident, concluded that it was most likely a coup carried out by extreme Hutu members of Habyarimana's government. This theory was disputed in 2006 by French judge Jean-Louis Bruguière and in 2008 by Spanish judge Fernando Andreu. Both alleged that Kagame and the RPF were responsible. At the end of 2010 the judges succeeding Bruguière ordered a more thorough scientific examination, which employed experts in ballistics and acoustics. This report seemed to reaffirm the initial theory that Hutu extremists assassinated Habyarimana. But the report did not lead the judges to drop the charges against the RPF suspects; this was finally done in 2018, due to lack of evidence.