"The bus couldn't be driven because there was blood everywhere."
Mr Froggatt said the driver learnt yesterday he had bone fragments in his cheek, requiring reconstruction surgery.
Selwyn College principal Sheryll Ofner called the incident completely unacceptable and said there had been "a wave of condemnation" from students.
"There has been real concern that the incident blemishes the school and harms the community they love being part of," she said.
They planned a gesture of support and sympathy.
The principal said she had suspended the alleged offender, pending a meeting of the school's board.
She said the school was not notified of a report the driver lodged with NZ Bus about an incident involving the same boy several months ago, in which the teen abused the man after being ordered off the bus for eating fish and chips.
"Had it been notified, we would have been able to handle it," Ms Ofner said.
Inspector Mark Benefield of Auckland police confirmed that officers were investigating Monday's attack.
"A 14-year-old pupil has been spoken to by police. He is now involved in the Youth Aid process."
Although the driver remained conscious, Mr Froggatt said he had suspected concussion. The man felt too sore and battered to receive visitors or talk to the Herald, but told him by phone how the punch came from nowhere.
"He was dealing with some cash customers when this kid appeared in the door and whacked him one. He said he just saw a blur and all of a sudden a fist came at him."
Mr Froggatt praised another student for fetching a deputy principal to the scene. But he claimed NZ Bus failed to send management representatives to assess the situation and support the victim.
He suggested the attack might not have occurred had the company taken action over the earlier incident.
NZ Bus operating chief Shane McMahon said the company was shocked and would hold its own investigation into Monday's attack.
"There's a bit of disbelief that you get a student behaving in this way."
He said the company was providing full support to the driver, who was treated at Ascot medical centre before going to Auckland City Hospital for a CT scan.
The good Samaritan who suffered a serious head injury at the hands of a violent youth has shown support for the bus driver.
Upon hearing about the attack North Shore woman Lucy Knight, who was left fighting for her life after thwarting a bag-snatch attempt, posted about the bus assault on Twitter.
"I cannot even begin to express the outrage & distress I feel reading a 14yo (sic) 'king hit' a bus driver," the mother-of-six wrote.
"Good luck with that Youth Aid. *frowns*(sic)."
Punch out of blue
• A bus driver faces reconstruction surgery after being punched in his seat by a teenager.
• The seat was drenched in blood and a replacement bus was sent to carry other students home.
• Selwyn College principal says students are united in their condemnation of the incident.
• NZ Bus chief says he has "never seen anything like this" and pledges full support for the driver.
