 THE leader of the school party who tackled a killer polar bear was hailed for his bravery yesterday as organisers announced the expedition was being abandoned.  Michael "Spike" Reid shot the bear which mauled to death 17-year-old Horatio Chapple in the early morning horror.  Reid, 29, and Edinburgh-based co-leader andy Ruck, 27, were last night preparing to be transferred to a British hospital after undergoing surgery for serious head and neck injuries in the "vicious" attack.  Two teenagers sleeping in the same tent as Chapple when the bear attacked, and who were less seriously hurt, were also due to be flown home.  Reid's father said his son had described the drama in an e-mail sent from his hospital bed.  The former headteacher said: "He told us the bear attacked the tent with three people in it, and he and another leader went to help and were viciously attacked by the bear.  "He managed to get away, ran to get a gun and shot the bear."  The father said he did not want to use the word "hero" to describe his son but added: "The other members of the group said he was very, very brave."  He added: "We were devastated and very worried.  "a lot of the day, we've been thinking about the family of the boy who died. There's a family in Wiltshire who have lost their son. For us, their grief must be unimaginable.  "This was such a rare and unlikely event, it was inconceivable."  The drama, which happened at 7:30am on Friday on the northern Norwegian islands of Svalbard, has now led to the rest of the month-long trip being cancelled.  The campsite which was attacked housed 13 of some 80 members of the British Schools Exploring Society (BSES) party, who will now all come home.  More details of the desperate struggle to tackle the rampaging animal emerged yesterday, but it remained unclear whether or not a trip-wire warning system that should have triggered flares to scare off the bear had activated.  It is thought the animal may have been so hungry it ignored any alarm that went off.  One of the injured teenagers, 16-year-old Patrick Flinders punched the bear on the nose and another attempted to fire at the animal.  Reid, from Plymouth, then grabbed a rifle and shot the bear. The two injured schoolboys, who were less seriously hurt, were Scott Bennell-Smith, 17, from Cornwall, and Patrick Flinders, 16, from Jersey.  The four are recovering from surgery in hospital in Tromso, 400 miles to the south of Svalbard, on the northern Norwegian mainland.  Some of their parents, including Flinders' father, Terry, have flown to join them.  The group had set up camp on Thursday on barren, rocky ground near the Von Post glacier, 25 miles north of Longyearbyen, the islands' main settlement.  Reid's sister, Juliet, 33, said the family had heard that the bear did trip warning wires placed around the camp.  She said: "We believe one of the young explorers tried to shoot the bear with a rifle but didn't manage to hit it.  "We believe Michael took the gun and shot the bear but didn't kill it."  The animal is thought to have been killed by another member of the group.  Reid is an events coordinator for the Royal Geographical Society in London where the BSES is based.  Flinders is said to have repeatedly punched the bear on the nose after it lunged into the tent.  His father, Terry, said: "The bear got into the tent where Patrick was with two friends, and he just, for some reason, grabbed hold of the other boy and just killed him.  "I don't really know why he chose the other boy - perhaps he was the closest one.  "Patrick, I think, was probably in the middle, because he grabbed hold of his head next, and then his arm, and I don't know how Patrick got out to be honest.  "Unless it was when the guy came in and shot the bear and maybe that's how Patrick got away with it, because they actually shot the polar bear, but the young lad was already dead."  Flinders said he had been told trip-wire failed to work.  He said: "This time it didn't happen apparently, and one of the other chaps came out with a rifle and tried to kill the polar bear and didn't do it.  "and then the leader tried to kill the polar bear, but just before he killed him apparently, the bear mauled him and he's really, really bad."  a school friend of Flinders said he was stunned to hear of the attack.  Wesley Riant, 16, said: "It's a bit of sh 