BAGHDAD, Iraq (CNN) -- Stressed-out soldiers are drinking whiskey and downing painkillers to try to cope with "mentally draining" duty in Iraq, a private testified Tuesday.

Troops turned to alcohol and drugs as they dealt with fears of being attacked and killed, Pfc Justin Cross said.

"It drives you nuts. You feel like every step you might get blown up. You just hit a point where you 're like, 'If I die today, I die.' You're just walking a death walk."

Cross described what was going on in his unit to a military hearing that will decide whether courts-martial will be launched against serving colleagues accused of raping an Iraqi girl and murdering her and her family in Mahmoudiya, south of Baghdad, five months ago.

The Mahmoudiya inquiry is one of several examples of alleged atrocities committed by U.S. troops in Iraq now being investigated.

Soldiers began recounting the killings of a raped teenager and her family when they were being given stress counseling after two other members of their unit were kidnapped from a checkpoint and killed. The killings of the soldiers "pretty much crushed the platoon," Cross said.

"For a while we were down, but we got back."

The unit also lost of all its belongings on February 5 when the building in which they were living burned down.

Cross said his unit went on long rotations outside its forward base, sometimes spending several weeks without hot food and showers or contact with family and friends. He testified that he and other soldiers were constantly in fear and said the unit was "full of despair."

The Army's surgeon general, Lt. Gen. Kevin Kiley, said last month that deployments in Iraq put heavy mental stress on troops and that some will need counseling.

Kiley said 15 percent to 30 percent of troops returning from Iraq have mental health issues but that was not unusual.

Up to one in 20 troops take antidepressants, the Army says, but cannot compare that to previous conflicts.

Mental-health teams have been sent to the front lines in both Iraq and Afghanistan to give support and Kiley is to head a new 14-member task force to recommend improvements in care for troops and their families.

Cross told the military hearing that some of those accused of rape and murder were among colleagues who drank whiskey and cough syrup and swallowed painkillers to cope with their jobs.

The accused soldiers were drinking whiskey when one of them raised the idea of raping the girl, according to earlier testimony in the Article 32 hearing that will determine if there is enough evidence for courts-martial where the suspects could face the death penalty.

Spec. James Barker, 23; Sgt. Paul Cortez, 23; Pfc. Jesse V. Spielman, 21; and Pfc. Bryan L. Howard, 19, face charges in connection with the killings in Mahmoudiya, south of Baghdad, on March 12.

Former Pfc. Steven Green, who was discharged from the Army in May because of an "anti-social personality disorder" and returned to the United States, is facing rape and murder charges in a civilian federal court. He is being held in a Kentucky jail.

A sixth soldier, Sgt. Anthony W. Yribe, has been charged with failing to report the alleged rape and killings but is not alleged to have been a participant.

All six men are from the 502nd Parachute Infantry Regiment of the 101st Airborne Division, based in Fort Campbell, Kentucky.

Cross said he saw Barker, one of the suspects, almost killed during a sweep for homemade bombs and said he survived because he was in a Humvee.

Iraqi authorities have identified the girl who was raped and shot to death as Abeer Qassim Hamza al-Janabi, 14. Her father, mother and 5-year-old sister were also killed.