Ufa, Russia ? Fifteen-year-old Arsen Masagutov headed off to Spain eager to hunt for amphibians he had not encountered in the creeks and ponds around his central Russian home.

Now his mother weeps ceaselessly. His father twirls stalks of wheat plucked from the German field where wreckage of the charter jet carrying Arsen and 44 fellow students fell after colliding last week with a cargo plane at 35,000 feet.

Radik, left, and Guzel Masagutov, parents of Arsen Masagutov, 15, grieve at a portrait of their son at home in Ufa, Russia. Arsen Masagutov was one of 45 children from Ufa killed when a Tu-154 jet slammed into a Boeing cargo jet over Germany. The children had been heading to Spain's Mediterranean coast for a beach vacation and cultural program as a reward for being outstanding students.

Their grief is mixed with the need to know who was to blame. So far investigators have focused on Swiss air traffic control, which had taken over the flight paths of the two planes shortly before they rammed together over Lake Constance.

“Where was the much-praised Swiss accuracy and reliability that night? They give watches with a 100-year guarantee, but they couldn’t separate two planes in the empty sky,” Guzel Masagutova, Arsen’s mother, said bitterly in her tidy, modest Ufa apartment.

The student group from the city of Ufa was headed to a beach town near Barcelona. The trip was an end-of-school reward for students who had earned top grades.

Arsen was making his first journey abroad, and the budding biologist was excited at the prospect of studying amphibians along the Mediterranean.

The boy was only allowed to go after the father of his best friend, Kirill, called Arsen’s parents to say that Kirill would only go if Arsen did.

The Masagutovs said they paid $830 for the two-week trip, canceling plans to travel together on a summer bus tour through Europe.

15 stalks of wheat

When the horrible news arrived, the Masagutovs said they were tortured by their decision. Driven by shock and grief, they flew with other victims’ families to Germany to see the crash site on Thursday.

Before leaving Germany, they collected a fistful of soil and 15 stalks of wheat from the field where the Tu-154 Bashkirian Airlines jet fell to earth.

Arsen’s mother spends most of her time now in his room, where he continues to smile down from a large portrait.

Exotic lizards slither around his aquarium. His belongings lay neatly folded on the shelves, and his school shoes are well polished.

“He was like a small aristocrat, striving to do everything correctly and with a smile,” Radik Masagutov said of his son.

“He could face down pain and wouldn’t hurt a fly.”

Masagutov, a psychologist working on his doctoral dissertation, admits that his academic credentials do nothing to help ease the sorrow.

“I thought at first that we should have died with him. But then Guzel and I decided to try to have another child. Perhaps Arsen’s soul will transplant itself,” he said.

Condolences pour in

Arsen Masagutov

The Masagutovs’ phone rings constantly with offers of support and condolences. Police and medics stop by to collect documents and materials to help identify Arsen’s body.

“We very much hope that the investigation is conducted carefully. We’re pinning our hopes on Germany,” Guzel Masagutova said.

A Russian plane is to leave today for Germany to return identified remains for burial in Ufa, said Deputy Prime Minister Viktor Khristenko, who is leading the government commission investigating the crash.

At School No. 91, which Arsen and three other crash victims attended, classmates have been showing up every day since the crash, despite the summer holidays. They place flowers and candles on the steps, sitting and sharing memories of their friends.

“They shined like stars. And they were abruptly extinguished,” said classmate Dasha Kolosnitsina, clutching a Valentine’s Day card from one of the slain students, 14-year-old Dennis Dinislamov.

“I will always be with you,” it read.