There is an international convention on this sort of thing and airlines are (I believe) obliged to give you compensation for immediate necessities. You should be able to get hold of KLM at the airports they fly to and get from them a number that you can ring in order to in effect announce your parents will buy toothbrush, paste, etc. toiletries needed overnight, also things like underwear socks, shirt/blouse - and see what KLM say. You need to remember two things: be reasonable (no Gucci, etc.) and keep all receipts (they will want them). Claiming from travel insurance comes after this because, as said elsewhere, the baggage is likely to arrive around 24-30 hrs after arrival. An insurance claim will only come in if the baggage is lost completely, otherwise most insurance is not worth claiming from due to "excess" deduction and future complications due to having claimed. KLM completely stonewalled my complaint when they ignored EU legislation on the consequences of "bouncing" me off a flight which was neither full nor had it left. Their prices are competitive but their service frequently stinks, although their cabin crew are generally average or better in attitude/helpfulness.