The problem areas are the slides or diving towers. There, on warm days, many people queue up in open-air pools. Sometimes a wrong look, a saying or a bump causes aggression – especially among teenagers and young men. One insults the other, they push, then hit. In many cities, pool operators are increasingly using private security guards who then intervene. If de-escalation fails, the police come.

Summer has just started, and recently police officers had to come to Berlin’s open-air pools at least three times to calm the situation, catch thugs and support the security services in closing the pool. On Wednesday, 40 to 50 young people rioted on a slide in Neuk├Âlln. The announcement said: “The bathroom will be cleared. Please pack your things and go to the exit. For safety reasons, the bathroom will be cleared.”

The phenomenon of bullying and rampaging young people and young men in outdoor pools is well known – and is primarily considered a problem in big cities. There have also been riots, closures and police operations in D├╝sseldorf and some cities in the Ruhr area in recent years. Recently, a mass brawl broke out in Mannheim after a dispute between two groups. According to a media report, there were several violent incidents in Saarlouis. If you search the internet for corresponding videos, you will come across scenes from loud, overcrowded baths, full of rebelliousness and aggression.

According to the German Society for Bathing, an association that also represents around 2,800 outdoor pools, disrespect is one of the reasons for more conflicts. “The problem is guaranteed not to decrease. This summer season will show whether it will become an increasing trend. But we expect more cases,” says spokeswoman Ann-Christin von Kieter of the German Press Agency. Not only swimming pools are affected. “Aggressive behavior is increasing, even against police officers or firefighters.” There are also riots in stadiums, parks or shopping centers.

In principle, the danger in outdoor pools in big cities or in problem areas is higher than in the country, says von Kieter. “The fuller the baths are, the greater the potential for conflict.” The aggression almost always comes from groups of male adolescents or young men. Something similar can be heard from the Federal Association of German Swimming Champion. Colleagues in particular are affected and are also threatened, complains association president Peter Harzheim. “The problems are very much concentrated in bathrooms in big cities.”

Everyday life in swimming pools is mostly quiet: Swimmers stoically swim their lengths, families stand for fries, guests sunbathe – on the vast majority of days nothing unusual happens in the pools with millions of bathers over the course of a long summer. Riots are isolated cases, but they make big headlines – and make some visitors feel uneasy.

Conflict researcher Andreas Zick from Bielefeld University sees no direct connection between swimming pools, hot days and aggression. There were only recently group brawls in public places in North Rhine-Westphalia in the evening. In summer, many people are just outside more, often in larger groups. Special situations and social factors are also decisive for aggression in outdoor pools.

“Most violence occurs between groups, even if it can start with a personal dispute,” says Zick. “Then others intervene because a member of the small or larger group was allegedly or actually attacked.” If there are still spectators “who celebrate the violence as an experience, then it escalates, and then the staff is often involved.”

Many operators have been relying on increased security measures for some time. Security guards check bags at the entrance, walk around in pairs and address noisy groups. On hot weekends, up to 170 security guards are on duty in Berlin, which costs 1.5 million euros a year. In addition, many baths impose house bans – in Berlin alone there have been 730 bans in the past five years. It was mostly about violations of the house rules, less about violence. But the bans can hardly be controlled, say conflict pilots. There are always problems with the same men.

“Violent assaults in swimming pools are not a brand new phenomenon. Bodily harm offenses occur in these places with a certain regularity,” says Alexander Poitz, federal vice president of the police union (GdP). There are fewer riots. “Much more often two or a few people come together,” he says when asked by the dpa. “What’s newer is that bystanders get involved in the conflict, form different camps and escalate.” Such incidents quickly caused a stir on the Internet. Police officers who were summoned would also be attacked.

Several operators have also recently taken action in NRW. There are more security guards on duty, says a spokesman for WasserWelten Bochum. “We also use lifeguards who are trained in safety.” So far this summer there have been no major incidents.

Berlin is taking further steps. The police should be present in front of selected outdoor pools with so-called mobile guards. In addition, in response to the bullying young people in two pools with frequent incidents, diving towers and slides were closed until further notice. The victims are children and peaceful bathers. “The decision was not easy for us,” says Johannes Kleinsorg, manager of the baths. “However, it is clearly these attractions that keep attracting rioters.”