Fukushima disaster

Just watched PBS 1-hour report of Fukushima nuclear disaster. It seems like Fukushima disaster can be avoided if one of the following three conditions was met: 1) Diesel generators are placed high above ground 2) Backup mobile electric trucks, if all Diesel generators fail, should be always available next to nuclear power plants in case of totally ravaged connection roads 3) Mechanical pressure values, rather than the electrically controlled values, should be designed on the roof of protective dome to release the build-up of hydrogen before the fuel rods start to melt. Actually, the turning point of Fukushima disaster did not happen until the Tokyo firefighters risked their lives to spend one hour to ship the water hose next to the highly radioactive plants. After water cannon from the hose was working to cool the core, the crisis started to subside significantly, 9 days after the tsunami struck.