Grieving dad murders air traffic controller

A grieving father is believed to have murdered an air traffic controller who was on duty when a plane crash killed dozens of children.

Police believe Peter Nielsen was tracked down and stabbed to death in a revenge attack on his own doorstep.

The killer is thought to be the parent of one of the children who died when a Russian airliner collided with a cargo plane, killing 71 people.

Much of the blame for the disaster was laid at the door of Swiss air traffic control after it was revealed that Mr Nielsen was the only man on duty at the time the aircraft exploded in flames over the German town of Uberlingen, on Lake Constance.

The tragedy 18 months ago happened when the air traffic controller wrongly instructed both planes to descend.

Police are looking for a German-speaking man, aged 50-55, who appeared at the house near Zurich at 5.45 last night.

He rang the doorbell, asked a question, then after a "fierce argument" pulled out a knife and stabbed Mr Nielsen "repeatedly" before running off. Neighbours called police but Mr Nielsen bled to death before an ambulance arrived.

The attacker was described as having dark hair, three days' growth of beard and spoke "broken German" with a Slavic accent. Swiss police have launched a massive manhunt.

Spokesman Martin Sorg said: "The enquiries are certainly heading in the direction that there is a link between the crash and the killing."

There is speculation that the killer was angered that compensation payments in an out-of-court settlement - reported to be £200,000 for each life lost - has been paid to the families of the 11 crew who died while a final settlement for the relatives of the 52 Russian schoolchildren has not yet been achieved.

Skyguide, the Swiss air-traffic control company, said it was appalled by the murder and that its employees "were in shock". Police have given special protection to other air traffic controllers and there has been a 40per cent reduction in the number of planes allowed into the air space as other controllers are treated for shock.

Mr Nielsen, a Dane who had been in Switzerland for five years at the time of the crash, lived with his wife and three children in a suburb near the airport in Zurich.

He had counselling after the disaster and was removed from duties. It is not clear if he had returned to work.