The PSNI revealed a number of details about the father who survived the attack on a van in east Belfast on Friday morning.
The explosion happened in the Hillsborough Drive area off the Woodstock Road in the east of the city just after 7am.
The senior prison officer who was hurt in the blast was later declared to be in a stable condition in hospital.
In a press conference on Friday, Assistant Chief Constable Stephen Martin said the victim had just left home to drive to work.
Detectives are examining whether the bomb dislodged from the vehicle as it was going over a speed bump, thus lessening the impact of the blast.
The Woodstock Road is a predominantly unionist/loyalist area.
Mr Martin said: “The intention of this device was to kill, someone prepared this device, someone transported this device and someone planted this bomb.”
The police commander added: “This could have been a fatality, the people who planned this wanted to kill a prison officer.
“This is a 52-year-old man, he has been in the prison service for 28 years, he’s a married man, he has grown-up daughters, and we could be facing an absolutely tragic set of circumstances today in which a man who goes to work every day to keep people safe, to protect people, is actually deprived of his life in the most callous of circumstances.”
Initially, as the incident was still ongoing, the PSNI had said in a statement: “A number of houses in Hillsborough Drive are currently being evacuated and an emergency evacuation centre has been opened up at the Salvation Army on the Cregagh Road.
“We are appealing for anyone who may have witnessed any suspicious activity in the Hillsborough Drive area or surrounding area over the past 24 hours to contact police on the non-emergency number 101 or on Crimestoppers on 0800 555 111.”
Earlier rumours that two victims had been taken to hospital were incorrect.
East Belfast MLA Chris Lyttle has expressed his outrage at the attack.
The Alliance MLA said it was a “sickening echo of the past”
“I am shocked and sickened someone has attempted to take the life of this man,” said Mr Lyttle.
“It is difficult to put into words the contempt every right-thinking member of society will have for those behind this attack. The people responsible offer nothing except death, injury and disruption.
“Those trying to return Northern Ireland to a climate of fear will not be allowed to win. My thoughts and prayers are with those injured by this device, and I would urge anyone with information about this incident to contact police immediately.”
Sinn Fein MLA Gerry Kelly said: “This attack on the Woodstock Road in East Belfast was wrong and I totally condemn it. There can be no place for such attacks in our society.
“I hope that the man injured in this incident makes a full and speedy recovery.
“Those behind attacks like this represent no one and have nothing to offer the community.
“They need to listen to the views of the vast majority of people in our society call an immediate end to this futile actions.”