The parents of a teenager stabbed to death outside a Liverpool youth club said they were "devastated" and urged his attackers' parents to help them.
Joseph Lappin, 16, was outside Shrewsbury House Youth Club, Everton, on Monday night when he was attacked.
Two teenage boys have been arrested on suspicion of murder.
Toni Lappin said: "As a mother I would appeal to all the mothers of those involved - understand our grief, come forward."
"The events of the last 24 hours have left us devastated," Mrs Lappin said.
"We have lost our son and his younger brother and sister have lost the person they looked up to."
A 17-year-old teenager from Old Swan was also stabbed but his condition is not thought to be life-threatening.
A third boy suffered minor injuries.
It is thought the three friends were waiting for their lift home when they were attacked.
They had been to the Monday Night Music Club, which is attended by youngsters who are learning to play instruments.
Mrs Lappin spoke at a press conference alongside her husband John.
She said: "Joseph was a lovely lad, our son and the centre of our family.
"He went out last night with friends, like teenagers across the country, and because of the events of last night he won't be coming back to us."
Mrs Lappin said her son had been an army cadet for three years, had never been in any trouble and planned to join the army.
"We believe that there was a large group involved in what happened last night," she said.
Mrs Lappin told the families of those involved in the attack that they had the "power to do the right thing" and "to make sure another family doesn't have to go through what we are going through now".
John Hutchison, manager of the Shewsbury House, said there was "much work" to do to restore confidence at the youth club.
He said: "The club staff and members have responded brilliantly and helpfully to the awful events which took place last night and the club will do all it can to offer care and support to those involved, especially to the victim's families.
"The tragic death of another teenager in what must be a pointless attack makes the work of clubs like Shrewsbury House all the more essential."