Authorities conducting DNA tests of the victims in a cable car accident at a ski resort in western Austria said Tuesday that six children between the ages of 11 and 13 were among the nine victims. The members of the German ski group died when a helicopter accidentally dropped a heavy tub used to carry concrete onto a cable car Monday. Police said three in the gondola that was struck had died, along with six others catapulted out of a nearby cable car. Rudolf Koll, a senior official at the Innsbruck prosecutor's office, told Austria Press Agency that the children were between 11 and 13 years old. DNA tests were necessary to identify three of the victims. Austria's vice chancellor, Hubert Gorbach, promised a thorough investigation into the accident, which occurred at the ski resort town of Soelden, 40 kilometers (25 miles) southwest of Innsbruck and some 500 kilometers (300 miles) west of Vienna. Neither human error nor technological defect were excluded as potential causes of the accident, he said.