Among extraordinary experiences at the Canberra Hospital and John James private hospital two mothers rejoiced in their new sons and reeled when the sky lost its sun.

Helen Morris and husband Gary rang their family in Banks to invite them to Canberra Hospital to celebrate their son Joshua's arrival just as the fires entered Canberra.

Their family couldn't come because roads from Tuggeranong were closed. Only then did the parents recall their pre-dawn drive to the hospital along Yamba Drive, seeing Brindabella Mountains glowing with fierce flames heading towards the sleeping city.

They had wondered why the fires, so apparent from the night before, had not been the subject of urgent warnings over the radio.

Mrs Morris, a teacher, had arrived at 4.15am eight days overdue, and walked endlessly singing Advance Australia Fair to bring on her baby.

At 9am she wandered outside under a cloudy bright sky. Joshua was born about noon. After 3pm she walked outside again, stunned to see street lights.

Patients began to smell smoke through the air conditioning. A disaster alarm had rung.

''About lunchtime, there was an announcement, 'could all non-vital patients please go home'. They released staff to go home,'' Mrs Morris said.

Staff had tried to discharge her that evening, but couldn't because roads were closed. She left the next day, learning her father in-law John Morris had been on the roof at Forsythe Street with a hose during the height of the fires, as were owners of many other homes.

When John James went on evacuation alert Heidi Mahon's epidural sedation was stopped so she could get to her feet if needed.

''While I was counting contractions we could see embers raining down around the hospital and then the sky, which was blood red, turned black as night.''

After a caesarean section to deliver her son Duncan, her obstetrician couldn't recall whether her eyes were stinging from smoke inside the hospital, or from earlier leaving work to save her home.

Ms Mahon's ordeal at John James worsened when her then husband, Peter Marshall, left to secure their home at Wanniassa.

The pharmacist wondered whether he and their home were safe while the hospital's power came on and off, and the city's phone lines were jammed.

''Yes, I was lucky in the end that I'd had an epidural. The catheter was still in my spinal column, so when the decision was made to do an emergency C-Section, I was given a full spinal block.

''I found out later they had people on the roof of John James hosing down live embers. They didn't tell me at the time.''

Instead the delivery team joked, urging her to call her baby Ash or Blaze. ''A week later, when I was released from John James, I came out to a Canberra I didn't recognise,'' said Ms Mahon, now living in Queensland.