As American forces bombed a Doctors Without Borders hospital in Kunduz, Afghanistan, on October 3, staff with the medical charity frantically reached out more than a dozen times, by telephone and text, to contacts at NATO, under which the US was operating, as well as the US Department of Defense. But, according to a report released by the group on Thursday, the attack continued for at least an hour, during which time NATO said it was "praying" for those inside the hospital -- even as its forces continued striking the facility and fired on those fleeing.

MSF, as the charity is known by its French acronym, says that at least 30 people, including 13 staff and 10 patients, were killed in the attack, which took place after days of intense fighting in the city. The incident led to a rare public apology from US president Barack Obama, and promises from American officials that investigations will be carried out. The US claims that the hospital was hit by mistake, and reports have indicated some officials believed Taliban fighters were making use of the hospital. While MSF says it was treating victims from all sides, including the Taliban, it denies that armed Taliban fighters were present on the night of October 3.

"The view from inside the hospital is that this attack was conducted with a purpose to kill and destroy," said Christopher Stokes, MSF general director, in a statement. "But we don't know why."

MSF says that it repeatedly relayed coordinates of the facility to defense officials in the days prior, and contends that US forces and NATO were well aware the facility was a hospital. But in its findings, the charity said that "a series of multiple, precise and sustained airstrikes" targeted the main hospital building. "This specific building of the hospital correlates exactly with the GPS coordinates provided to the parties of the conflict," wrote MSF.

First hit was the intensive care unit, where a number of patients were being treated, including several hooked to ventilators, and two children.

"MSF staff were attending to these critical patients in the ICU at the time of the attack and were directly killed in the first airstrike or in the fire that subsequently engulfed the building," wrote the charity. "Immobile patients in the ICU burned in their beds."

Those who were able to flee the hospital suffered similar fates. MSF staff reported that people running from the hospital were in several instances on fire, and that they subsequently fell to the ground unconscious. A patient in a wheelchair was "attempting to escape from the inpatient department when he was killed by shrapnel from a blast." Another hospital staff member was decapitated by shrapnel, according to the report.

"Many staff described seeing people being shot, most likely from the [US] plane, as people tried to flee the hospital building that was being hit with each airstrike," reported MSF. "Some accounts mention shooting that appears to following the movement of people on the run. MSF doctors and other medical staff were shot while running to reach safety in a different part of the compound."

The report lists multiple attempts to contact NATO, American forces and the UN during the onslaught. Starting at 2.19AM local time, an MSF staff member in Kabul called NATO's Resolute Support mission based in the country to inform it that the hospital had been targeted. Over the next hour, MSF staff made more than a dozen calls and sent text messages to relevant authorities, to no avail. At 2:52, in response to an earlier text frantically notifying the mission of ongoing attacks, a NATO representative texted back, "I'm sorry to hear that, I still do not know what happened."

At 2:59AM, after nearly an hour of attacks on the hospital, Resolute Support texted MSF in Kabul, saying "I'll do my best, praying for you all." The strikes finally ceased sometime between 3AM and 3:13AM, according to MSF's report.

Sarah Knuckey, director of Columbia Law School's Human Rights Institute, said the report suggested there was no legitimate basis for targeting the hospital.

"What is needed from the US government is a minute by minute explanation of what the attacking forces knew and when, and what decisions were made, and on what basis." said Knuckey. "In particular, the US needs to explain what legally required precautions it took or failed to take to avoid civilian harm."

Knuckey added that the report's reference to attacks on fleeing staff and patients "may amount to violations of the laws of war, and require individualized investigations and responses from the US government."

Reached on Thursday, a NATO spokesperson with Resolute Support said the mission could not not comment on the MSF report due to ongoing investigations.