Sydney train commuters caught up in a network-wide outage may not receive a refund as the NSW premier waits to be told what went wrong.
Gladys Berejiklian has again apologised "deeply" for Saturday's meltdown when some trains were halted between stations and commuters were warned to avoid all non-essential travel.
Sydney Trains blamed "technical issues" for the problem that affected the network for more than 24 hours.
Ms Berejiklian has asked for an explanation into what caused the issues.
"I'm getting advice today," she told reporters on Monday.
"I don't want to see anyone inconvenienced in that way, especially when we had so many sporting events."
But she avoided committing to refunding affected travellers.
"We always leave the door open for the future."
Sydney hosted the Wallabies and All Blacks rugby union Test, the Sydney AFL derby and three NRL matches on Saturday.
"Can't believe Sydney Trains made me 2.5 hours late to work and charged me $4.73 for the privilege," Twitter user Palooka posted on Saturday.