years from 197a to 1982, and it has been operational since 198a, and it has been closed for flood defence purposes on 207 occasions now. so thatis purposes on 207 occasions now. so that is 207 times london has been under threat, that is 207 times london has been underthreat, but that is 207 times london has been under threat, but because of the thames barrier and associated defences, londoners and visitors to london have been able to go about their normal business staying safe from that danger. their normal business staying safe from that danger. let s ust say the thames barrier h from that danger. let s ust say the thames barrier did from that danger. let s ust say the thames barrier did not from that danger. let sjust say the thames barrier did not show- from that danger. let sjust say the thames barrier did not show up - from that danger. let sjust say the thames barrier did not show up in l thames barrier did not show up in time or there was a model that was not as efficien
about the last third of the exit would have been this wading through caverns which have been drained of water. so not as perilous as the early stages, but i think it s given people a lot of hope that those four have emerged. but with torrential rain here tonight and a huge catchment area with water feeding into that underground cavern system and the water table rising, concern growing for the eight remaining boys and their coach left down below. right. the more water, the less air generally speaking. do the other boys and the coach inside the cave have any idea that these first four have made it to safety? reporter: we don t know that yet. we ve had a briefing from the governor this evening who told us some details of the operation, but we don t actually know whether a diver has been down to bring the glad tidings of great joy to the others. what we do know is they have been properly prepared for this adventure. you know, they ve been trained how to use these full-face scuba