He saw it as an opportunity to travel and to check his possible reactions in extreme situations, so he seized it: his career in conflict zones had started.
Thielker´s most famous work is a photograph of Rwandan refugees carrying water back to a camp in Tanzania that won him a Pulitzer Prize in 1995.
At that time, he reported the Hutus and Tutsis overwhelming civil war together with Jaqueline Artz, Javier Bauluz and Jean-Marc Bouju.
He is known to be one of those photo journalists who have worked surrounded by confrontations with death, ethical issues and the consequences they witness when they report from conflict zones.
Thielker also performed consultancy for the daily newspaper Tageszeitung and for Internet Image Database (www.piaxa.com).