The weather conditions at 6.45 a.m. of 4 April were ideal for delivering a chemical weapon. Data based on historical weather forecasts indicates that the wind speed was just over three kilometres per hour from the southeast, that there was no rain and practically no cloud cover, and that the temperature was around 13 degree Celsius. The OPCW FFM, in the absence of actual weather data recorded for Khan Shaykhun and instead relying on actual weather data recorded at three other locations in the area, concluded that the wind speed was low with uncertain direction, most likely coming from somewhere between the south and east. All available data indicates stable atmospheric conditions without significant turbulence. Under such conditions, the agent cloud would have drifted slowly downhill following the terrain features at the location (roads and open spaces), in a southerly and westerly direction. This is consistent with the observed locational pattern of individuals becoming affected by the agent cloud.

The chemical bomb released a cloud which spread over a distance between 300 and 600 metres from the impact point and killed at least 83 persons, including 28 children and 23 women. One interviewee said that most of those severely affected, including many who died, were within 200 meters to the south and west from the impact point of the bomb, while most of the ones less seriously injured were further away. Many of the deceased victims were buried in Khan Shaykhun.

Some of the victims died in bed and their bodies were not found until later on 4 April. A single mother who was out farming returned home to find all her four children dead. The body of one orphaned girl was found the following day. Also on 5 April, one interviewee found the body of a woman and her six children in a basement, where they had apparently tried to take shelter from the gas released by the chemical bomb. Another interviewee described how, on the way to his family’s home, he witnessed people dying in the street and children desperately crying for the help of their parents. When he arrived at the house, he found his niece dead and his two sisters struggling to breathe. He lost consciousness shortly afterwards and woke up in hospital where he learned his sisters had died. In total, 293 persons, including 103 children, were injured. Medical practitioners expressed particular concern over parturient women and the effects that the toxic agent posed to their unborn babies. A lack of access to adequate medical equipment however prevented doctors from establishing whether foetuses were affected.

Upon learning of the airstrikes, civil defence teams from Khan Shaykhun and from neighbouring Heish went on location to assist in rescue efforts. They were unaware at the time of the possibility of the release of a chemical agent so they did not carry respirators or other protective equipment. Several fell ill upon arrival to the scene, and at least two died. When they realised a chemical agent may have been present, rescuers warned incoming teams of first-responders who carried respirators with them. Some of those using respirators reported that, despite this protection, they too felt affected by the gas. First-responders removed the clothes from victims, washed them with water, and provided them with oxygen masks. Several medical workers said that first-responders may have inadvertently exposed victims to additional quantities of sarin by removing the clothes on their upper bodies over their neck instead of cutting them off. By removing their clothes this way, victims would have inhaled sarin as the clothes passed by their mouths and noses.

After washing the victims, first-responders used ambulances, cars, and motorbikes to transport victims to several medical facilities in the area, with the al-Rahma medical point in Khan Shaykhun receiving approximately 80 victims. Others were taken to the al-Salam and al-Watany hospitals in Maarat al-Numaan, the Oday hospital in Saraqeb, and hospitals and clinics in Areeha, Ma’arat Misrin, Jarjnaz, Maar Shurin, Abdeen, Tal Minnes, Kafr Nabl, Banesh, Idlib city, Adnan Kewan, Haas, and Bab al-Hawa. Overall, these facilities were ill-equipped to deal with victims of chemical attacks other than chlorine — an issue compounded by the large number of victims and the severity of the symptoms from which they suffered.

Moreover, just one and a half days before the attack, on the evening of 2 April, Syrian and/or Russian forces carried out airstrikes which directly hit the Maarat al-Numan National Hospital, using at least three delayed fuse aerial bombs. The attacks against the hospital destroyed its upper floors where the inpatients room and intensive care unit were located. Most of the hospital’s equipment, including incubators, were also destroyed. The Maarat al-Numan hospital, located 24 kilometres north of Khan Shaykhun, is described by medical staff as the main hospital in the area and the one which could have more adequately dealt with cases of patients exposed to chemical agents. Before the strikes, it employed 300 staff including 20 doctors and over 100 nurses, some of which had received training to treat victims of chemical agents and who subsequently trained their colleagues. The hospital also contained large stocks of atropine, hydrocortisone, diazepam, and oxygen concentrators. As a result of the airstrike, the hospital could only treat some 15 victims of the 4 April chemical attack. One victim who was seriously injured by the gas released by the chemical bomb noted that first-responders took him to Maarat al-Numan National Hospital because they were unaware the hospital had been struck two days earlier. The hospital was unable to treat him, and he was subsequently transferred to another hospital.

Depending on what the healthcare facilities had available on 4 April, victims of the sarin attack were given atropine to help reactivate their heartrates, and pralidoxime to reverse chemical poisoning, though several medical staff reported that most hospitals did not have the latter or only had it in small quantities. Doctors noted that most of the existing pralidoxime had expired because, after the 2013 attack in Ghouta and the subsequent removal and destruction of Syria’s chemical weapons by the Joint Mission of the United Nations and the OPCW in 2013 and 2014, it was announced that chemical weapons such as sarin no longer existed in Syria. For these reasons, hospitals ceased planning for these types of attack. In the absence of alternatives, doctors administered the expired pralidoxime to patients. Owing to the high number of casualties, several hospitals ran out of atropine and requested other medical facilities to provide them with additional medication. To help them breathe, many of the victims were intubated and, where available, placed in respirators. At least 31 persons were taken from medical facilities in the Syrian Arab Republic to hospitals in a neighbouring country, where at least three subsequently succumbed to their injuries and passed away. Several medical workers noted that the combination of lack of appropriate and sufficient medication, overall shortage of staff, extremely reduced capability of Maarat al-Numan National Hospital, and consequent need to take patients to more distant health-care facilities all contributed to the overall high number of fatalities.

Al-Rahma medical point and the neighbouring civil defence centre operate from caves in the mountains, located approximately two kilometres from the centre of Khan Shaykhun. Rescuers took many of the victims directly from the area affected to al-Rahma where at least 25 persons died. Several interviewees explained that al-Rahma was not prepared to treat victims of chemical attacks but that patients were only taken there because it was the closest medical facility. Throughout the morning of 4 April, after the 6.45 a.m. airstrikes, interviewees saw drones over the skies in Khan Shaykhun and between 11.30 a.m. and 1.30 p.m., a series of airstrikes directly impacted the medical point and the civil defence centre, which were treating patients of the chemical attack. Airstrikes in Khan Shaykhun were reported until 4.00 p.m. Eyewitnesses further noted that the airstrikes which struck al-Rahma were conducted by jetfighters. As a result of the attack, the al-Rahma medical point was forced to transfer all intensive care patients to other hospitals without ventilators. Due to the lack of sufficient ambulances, many patients were transferred in civilian vehicles.

Interviewees further detailed that the medical point was struck at least three times over the span of a few minutes. One of the strikes destroyed the only external building of the medical point and several ambulances. Another strike hit the hospital’s upper floor and its warehouse destroying some equipment. Though there were no fatalities from the attack, some medical staff and patients sustained minor injuries. Photographs provided to the Commission show the main building and surrounding area were struck by aerial bombs. The building sustained a direct hit from at least one blast weapon and several shallow craters pockmark the site. Additionally, burned out remnants of what appear to be ZAB 2.5SM cluster incendiary munitions were found in scorched grasses dotting the area. In view of the fact that the Commission has previously documented Syrian and/or Russian air forces having used cluster incendiary munitions, that international coalition forces do not use these type of munitions, and that Russian and Syrian officials acknowledged that at the time of the strike, between 11.30 a.m. and 13.30 p.m., the Syrian air force conducted airstrikes in Khan Shaykhun, the Commission finds that there are reasonable grounds to believe that either Syrian and/or Russian forces conducted the airstrike against the al-Rahma medical point.