A number of world leaders and politicians had to postpone planned trips or were diverted and delayed due to the closure of airports and airspace : The funeral of President of Poland Lech Kaczyński and his wife , who died on 10 April 2010 in a plane crash in Smolensk , took place on 18 April . Due to the disruptions in travel , several national leaders cancelled their plans to attend , including Barack Obama , Stephen Harper , Angela Merkel , and Nicolas Sarkozy . Presidential aide Jacek Sasin initially said a postponement until later that day or even the following day was a " very serious alternative " , but it was later announced that the funeral would take place as planned . On 17 April , delegations from India , Japan , South Korea , Mexico , New Zealand and Pakistan confirmed they would not attend . Obama released a statement on Saturday afternoon saying that he would not be able to attend the funeral due to the traffic disruptions . He stated , in a phone call to acting President Bronisław Komorowski , " Michelle and I continue to have the Polish people in our thoughts and prayers ... " The travel plans of members of European royal families from countries such as the Netherlands , Norway , Sweden , and Spain were cancelled they had intended to travel to Copenhagen to celebrate the 70th birthday of Denmark 's Queen Margrethe . The Dutch , Norwegian , and Swedish royal families changed their plans from air to car or rail
plane crash
2010 Polish Air Force Tu-154 crash
Effects of the April 2010 Eyjafjallajökull eruption