Good samaritan saved son - mother

Terence Cassidy spent four days in hospital [Pic: Derry Journal]

A mother whose son was attacked in Derry city centre has said she wants to thank the good samaritan she believes saved his life.

Terence Cassidy, 17, was taken to hospital with serious head injuries after he was beaten up and left unconscious near Magazine Gate.

His mother Olive Quigley said he would have died if an unknown passer-by hadn't stopped and called 999.

"He was an angel from heaven," she said.

"I have to thank that man an awful lot, he's made me a happy woman today.

"I'd like to meet him some day, I would love to say thank you to him," she said.

The PSNI said it was investigating the incident.

"The assailant is described as being in his early 20s, about 5ft 9ins tall, with dark hair, and wearing a white tracksuit top and blue jeans," said police.