Professor Michal Pędziwiatr and his colleague, Professor Mateusz Wierdak, were having lunch with their families in central Krakow when they heard gunshots. Pędziwiatr told the news outlet Fakt that his son alerted him to the situation, saying, "Dad, they're shooting at people there, people are falling to the ground."

Upon arriving at the scene, the two surgeons treated both the police officers and the apparent attacker. Pędziwiatr stated that when it comes to saving lives, it does not matter who is who.

Once the shooting concluded, Pędziwiatr attended to the other victims and the apparent perpetrator, who required assistance. Meanwhile, Wierdak began treating a police officer who had been shot in the chest during the gunfight. Wierdak reportedly stuffed all the bandages into the officer's chest and stuck his hands in. Pędziwiatr told Fakt that if Wierdak had not done this, he did not know how things would have turned out because there was a long wait for the ambulance.

Pędziwiatr also contacted the John Paul II Hospital, specifically the Department of Thoracic and Cardiac Surgery. He told Fakt he insisted the officer be taken there because, in his opinion, the patient had the best chance of survival there due to the presence of specialists for that specific type of injury.

The shooting occurred on a Saturday in Krakow's market square, resulting in the deaths of six people: four women and two men, including four Polish nationals, a British man, and a non-Polish citizen whose nationality has not yet been disclosed. Sixteen others were injured, including Senior Police Constables Jakub Kulik and Artur Morański. Police also identified three bodies in the alleged gunman's apartment as the suspect's parents and sister.

The National Public Prosecutor's Office in Poland is investigating the attack, with a unit specializing in "terrorist offences" leading the probe. Additionally, six Dublin Civil Defence volunteers who were on a city break nearby provided medical aid, including CPR and hemorrhage control, according to officer James McConnell.