The Japanese army has abandoned its attempts to use a helicopter to pour water on the stricken Fukushima nuclear plant due to fears over radiation.
The race is on to avert a nuclear catastrophe.
But for many experts, this situation is becoming more and more desperate.
The name Fukushima looks set to feature among the worst industrial accidents in the world, along with others like Chernobyl and Three Mile Island.
Three explosions and a fire have damaged four of the six reactors at the plant in northeastern Japan, 240 kilometres north of Tokyo.
The Japanese authorities say only low levels of radiation have been detected outside the plant.
Reactor number 3 is currently causing the most concern at Fukushima. But scientists say what was thought to be smoke is in fact steam from water being poured on to cool the nuclear rods.
Reactor number 4 is also being watched closely after a fire yesterday.