A mother who was at a water park where an 11-year-old girl died said her own daughter felt unsafe and criticised a lack of “action” among staff during the incident.

Emergency services were called to Liquid Leisure, near Datchet, Berkshire, at around 3.55pm and the girl, who was reported missing, was found just after 5.10pm before being rushed to Wexham Park Hospital where she died.

Police officers were at the scene on Monday, with the aqua assault course set to reopen on Tuesday morning, according to staff, despite safety concerns being raised by parents.

A 41-year-old woman from South Buckinghamshire, who did not want to be named, was at the “busy” water park with her teenage daughter on Saturday, having been several times before.

The woman said the situation was “an absolute tragedy” for the family and friends of the girl while she and others at the park felt “shock” and “helplessness” at the scene.

The woman told the PA news agency: “My teenage daughter and her friend got in the water at 3pm for their session.

“I went off to get a drink and something to eat and then about 3:20 asked another mum already occupying a bench if I could join her.

“I started to try and make my daughter out because she was wearing a wetsuit and not many were, but because of the sheer numbers it was impossible so I just started to watch others.

“I quickly noticed not everyone was wearing life jackets and I saw a young female lifeguard closest to where we were sat not paying attention and staring across the open water rather than the people she was meant to be looking at.”

The woman said she began to feel “uneasy” about the ratio of lifeguards to visitors but added: “I reasoned with myself that my daughter and friend had their life jackets on and the session would soon be over.”

She said soon afterwards a lifeguard began to shout, telling them to get off the inflatable course.

She went on: “We then realised a child was missing as two frantic women ran past screaming the child’s name.

“There seem to be no plan of action with the LL staff. A few lifeguards jumped into the water and started searching in what appeared to be a very non-methodical way.

“Another member of staff started asking other members of staff if they were life guard trained. No one appeared to be in charge and there was no co-ordination in managing the situation.

“For the adults and children left on the riverside we didn’t know what to do, there was no communication and no evacuation procedure. There is one small entrance and exit at LL and the emergency services arrived quickly and in huge numbers, they couldn’t have done more.

“But because we weren’t told what to do and didn’t want to block their efforts of coming in to the park we just stood by and witnessed the search and rescue divers looking in the water.

“Afterwards my daughter commented that she didn’t feel safe on the inflatable, there were areas which had deflated and gaps between obstacles which anyone could have easily slipped down leaving them underneath the inflatable.”

The woman said her daughter had attended a safety briefing beforehand and said she was told not to push in people they did not know, not to use abusive language and that a whistle would be blown 10 minutes before the end and a second whistle would be blown when the session was finished.

The girl’s death is being treated as unexplained and an investigation has been launched, Thames Valley Police said.

Although formal identification has yet to take place, the girl’s next of kin have been informed and they are being offered support by officers.

Melissa Henson, a mother-of-two, claimed her daughter got stuck head-down in the water between two inflatables during an incident one year ago ago.

She told MailOnline: “This (the girl who died) could have been my daughter.”

Ms Henson told the publication after raising concerns to management about safety, they apologised and offered her a free return.

A Liquid Leisure statement said: “Our thoughts and prayers are with the family, friends and all those effected by this desperately tragic and upsetting incident.

“As Thames Valley Police are in the early stages of investigation, it would not be right for us to add further comment, but we will continue to fully support and assist them throughout the process.”

Its website says: “Liquid Leisure is home to Europe’s Largest Aqua Park and the first official Ninja Warrior UK Aqua Park, set on one of the most beautiful private freshwater lakes amongst stunning parkland in the heart of Berkshire.”

Emergency services, including Royal Berkshire Fire and Rescue Service, Buckinghamshire Fire and Rescue Service, Surrey Fire and Rescue Service and South Central Ambulance Service, were at the scene on Saturday afternoon.