Morrell had previously spent time in an At-Risk Unit due to his assessed risk of self-harm but was moved to a residential unit 12 days before his death.
"He knew other prisoners and staff in the residential unit and maintained phone contact with family and friends on a regular basis," he said.
"Every effort was made by staff to save him. Every death in custody is a tragedy. Since the man's passing we have maintained contact with his family, and offered them our condolences."
Beales added that prisoners and staff were also affected by his death.
But prisoner advocacy organisation People Against Prisons Aotearoa have accused Corrections of negligence.
PAPA spokeswoman Emilie Rākete said Morrell's death "could have been avoided if he had been provided with the mental health care he needed".
She raised concerns that Morrell had spent time in an At-Risk Unit, which she likened to solitary confinement.
"He needed help. Instead, he was abandoned in solitary confinement," Rākete said.
"Suicide is a tragedy, but it can be prevented. Abolishing solitary confinement and giving prisoners access to real mental health treatment is the first step towards ending prison suicides.
"This young man died alone, in a prison cell, uncared for, when he didn't need to. That is something we have to fix."
Corrections refuted the solitary confinement allegations, saying that while Morrell was in ARU, he was able to mix with other prisoners. He was also seen daily by health staff and assessed by the RFPS team twice weekly.
There was only one "unnatural" death in prison in the 2016/17 year - a suicide.
In the 2015/16 year there were 11 "unnatural" deaths recorded in New Zealand prisons and 26 cases of "self-harm threat to life incidents".
The figures increased from 8 deaths and 4 incidents in 2014/5, 3 deaths and 17 incidents in 2013/14, 3 deaths and 7 incidents in 2012/13 and 5 deaths and 6 incidents in 2011/12.
The PAPA-organised candlelight vigils will be held in Auckland, Wellington, Christchurch and Dunedin on Thursday evening. Speakers will include prison abolitionist and legal scholar Moana Jackson, University of Otago mental health professional Dr Keri Lawson-Te Aho, and Green Party MPs.
Where to get help:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
Or if you need to talk to someone else:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Need to talk? Free call or text 1737 (available 24/7)
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• Rural Support Trust: 0800 787 254.