A nine-year-old boy was orphaned after a 23-year-old gunman killed his mother, father and sister, 6, at an Iowa camp before shooting himself in an apparent 'random act of violence.'

Police said Arlo Schmidt, of Cedar Falls, was the sole survivor of the deadly encounter that took place Friday when Anthony Sherwin, of Nebraska, shot parents Sarah and Tyler Schmidt, both 42, and their daughter Lula. 

Arlo was uninjured, and Sherwin was found dead from a self-inflicted gunshot wound just west of campgrounds at the Maquoketa Caves State Park in Maquoketa, Iowa. 

It is unclear if Arlo was in the same place as his sister and parents when they were murdered, and further information about how he was spared has not emerged.  

A motive is also unclear.

Officials are unsure if Sherwin - who was visiting from La Vista, Nebraska, had any connection to the victims. DailyMail.com has contacted his family for further information. 

He lived with them in a neat apartment, and local police say he had no known criminal record.  

His Facebook page is completely blank, bar a black square that he used as his profile picture.  

And Sarah's sister, Jana Morehouse, mourned the loss of her sibling and called the attack 'a random act of violence.' 

Mitch Mortvedt, from the Iowa Department of Public Safety also suggested that the attack may well have been random.

'We don't know what led up to this, what precipitated it,' he said, adding that so far, 'the investigation has not revealed any early interaction between the Schmidt family and him.

Today, my life has been shattered,' Morehouse wrote. 'My beautiful, smart, funny, curly haired sister, her husband, and their 6 year old daughter were victims of a random act of violence while camping as a family in Iowa. 

Their 9 year old son was able to survive and has a lifetime of trauma ahead.' 

The family of the victims have set up a GoFundMe page to help support Arlo and set up an education fund for his future.

She added that it was unthinkable for life to go on without her sister or young niece.

I cannot fathom that [Sarah] will no longer be on the other side of the phone,' Morehouse said. 'I cannot fathom that I don't get to see Lula grow up.' 

Ceder Falls Mayor Rob Green, a neighbor of the Schmidts, also mourned the family's tragic death on Friday, urging residents to help support Arlo. 

Green, who knew Sarah as she worked at the Cedar Falls Public Library, wrote: 'Please offer some extra grace to the Schmidts' many friends, neighbors, and coworkers as we try to process this horrible tragedy.' 

By Saturday afternoon, the GoFundMe for the Arlo raised more than $66,000, with a Meal Train fundraising page also collecting $850 for the nine-year-old's food budget. 

Green and Morehouse described the attack on the Schmidt family as a 'random act of violence,' which appears to be the initial conclusion police have come up with. 

Police did not say whether or not Sherwin had a permit to carry a gun and did not disclose any information about the firearm used in the shootings. 

Mortvedt said autopsies on Sherwin and the victims will be conducted over the weekend.