Shocking CCTV footage shows the 27-year-old crossing the intersection of Hamilton Place and Campbell Streets about 1am.

As she reaches the middle of the road a tractor crane turns the corner, runs her down and appears to continue down the road.

Paramedics rushed her with critical head injuries to the Royal Brisbane and Women's Hospital where she underwent emergency surgery.

Ms Stevenson's social media accounts reveal the Sunnybank State High School 2008 graduate celebrated her 27th birthday in June.

On June 18, she posted a photo of herself surrounded by balloons, including a bright pink "27" balloon.

In 2013 she started working as a receptionist at Brisbane law firm Law in Order and worked her way up the ranks to become a business development executive at the company.

A 58-year-old man handed himself into police on Thursday but 24 hours later he had not been charged.

Police seized a tractor crane from Queensland Rail at Bowen Hills on Thursday.

Queensland Rail chief-executive-officer Nick Easy said it was a terrible accident and his thoughts were with the young woman and her family.

"This is a police matter under investigation," Mr Easy said.

"Queensland Rail is doing everything possible to assist emergency services with their inquiries."

Investigations were continuing.