Members of The Fire Brigade's Union are going on strike as I type this. As a result, some London Underground stations are closing this evening - but not all. London Underground has an interesting piece on safety on the tube:

Under normal circumstances, with full fire service cover, the risk of death to a daily traveller on the Underground from all causes is around 1 in 150,000 per year. The risk from fire is only a small contributor (about 2.5%) to this overall risk. [Source: London Underground]