A sudden loss of altitude, followed by a series of erratic turns, as the pilot desperately tried to regain control before the aircraft began spinning uncontrollably. The crash of a CH-47 Chinook helicopter assigned to Italy’s contingent in the European Union’s EUFOR Althea mission unfolded in a matter of seconds, just after takeoff.

The helicopter went down yesterday afternoon in northeastern Bosnia and Herzegovina during a routine operation. It crashed in an uninhabited area on the outskirts of Gorice, in the Brčko District.

The Defense Ministry confirmed that four people had been killed: “It is with profound sorrow that we announce that four service members died in the accident involving an Italian helicopter operating as part of the EUFOR Althea mission in Bosnia and Herzegovina: two members of the Italian Army and two members of the Italian Red Cross Volunteer Military Corps.”

The victims were identified as Army Sergeants Simone Ruggia and Claudio Marchesi, and Red Cross Volunteer Military Corps Lieutenant Franco Adriano Zecchillo and Sergeant Laura Procacci.

There were 15 people aboard, all Italian nationals. The 11 injured are receiving medical treatment, and none is in life-threatening condition, the ministry said. The Defense Ministry immediately arranged for an Italian medical team to travel to the site to provide the injured with additional support and care.

According to the initial reconstruction of the helicopter’s route, the aircraft had departed from Viterbo that morning, made a technical stop at Pratica di Mare Military Airport, and then continued to the mission area in Bosnia.

“It is truly an enormous tragedy. Italy is very much loved in this country and regarded as a friend. To pay such a price in human lives is terrible.”

Ambassador Sarah Eti Castellani spoke to La Stampa from a car taking her from Sarajevo to Brčko, a drive of about three hours. She confirmed that 15 Italians had been aboard the helicopter. The number of casualties and the condition of the injured, she said, “are changing by the minute, and the circumstances of the accident are still unclear. It crashed just after takeoff.”

“It is difficult to understand how this could have happened. Weather conditions were not unfavorable,” she said.

Italy has commanded the EUFOR Althea mission since January, under the leadership of Gen. Maurizio Fronda. But the helicopter was not taking part in a special exercise, Castellani explained.

“I don't know whether you can call it an exercise. This is a very frequent activity because much of the territory is mountainous, making connections more difficult. There was nothing unusual about it. It was a routine operation.”

The mission, a European-led force with NATO participation — including Turkey — has been operating for more than 30 years. It brings together 20 countries and approximately 1,600 troops. Italy currently provides the largest contingent, with more than 300 personnel.

This is not the first time Italian service members have lost their lives in the region.

“During the war in the 1990s, a transport plane was shot down while carrying aid, blankets and medicine for civilians under siege on Mount Zec,” Castellani said. “Italy is loved by all three constituent peoples because of its commitment to dialogue. During the war, many Bosnians took refuge in Italy — about 80,000 people. That is why there is such deep emotion today: a friendly country has been struck.”

Rescue teams reached the crash site quickly. The helicopter had been flying at low altitude before it went down. Local firefighters remained in the area throughout the night because of the large amount of jet fuel spilled on the ground, taking precautions to prevent secondary explosions.

“The causes of the tragedy are currently under investigation. The necessary inquiries have already begun to reconstruct the sequence of events and establish the circumstances of the accident,” the Defense Ministry said.

No possible cause has been ruled out. Among the hypotheses being considered are a medical emergency involving the pilot, a mechanical failure or a collision with high-voltage power lines visible in video footage.

The Boeing CH-47 Chinook, a heavy-lift helicopter with two rotors and a length of more than 15 meters, has for decades been one of the Italian Army Aviation’s main transport aircraft.