Preliminary findings released into what caused cracks in beams in Salesforce Transit Center building

SAN FRANCISCO (KGO) -- We are finding out more about what may have caused two structural steel beams to crack inside the Salesforce Transit Center.

RELATED: SF's Salesforce Transit Center has now been closed for as long as it was open

Holes cut into the steel along with thermal heat are likely to have contributed to those cracks.

On Thursday, the New York-based company which tested samples of the beam gave its preliminary findings. It was either the stress from the construction or the use of the building that caused these microcracks. That then contributed to the two larger cracks which forced the closure of the Transbay Transit Center.

TIMELINE: A look at the Salesforce Transit Center closure in San Francisco

Herrick Corporation was responsible for fabricating the beams that cracked. Its president underlined that these findings are preliminary.

Members of the Transbay Joint Powers Authority were told that a final report on the "root cause" of the cracks is expected by next month. In the meantime, a fix to the problem was presented Thursday.

RELATED: Funding to Transbay Joint Powers Authority suspended in unanimous vote

It's expected to be approved by the peer review panel of engineers within the next few weeks.