Police responded to reports of the argument in the 300 block of Fifth Street just before 9:30 a.m. and arrested two suspects, Officer GraceGatpandan said.
The construction worker, a woman who has not been identified, was working at a site on Shipley Street, an alley between Harrison and Folsomstreets.
"I saw a puddle of blood on the side, and realized it was more than that and that's when I called the cops," said one witness, who did not want to be identified.
After an argument there, she escorted two suspects, a man and a woman, away from the construction site. When she didn't come back right away,her co-workers went to check on her and found her stabbed, Gatpandan said.
The other workers saw the man and woman walking away and tried to stop them. They followed them to Fifth and Folsom streets and police arrived and arrested them, Gatpandan said.
The stabbed construction worker was taken to a hospital but died there a short time later.
Police have not released the name of the victim or the two suspects.
After firefighters cleaned up, flowers and candles are being left on the spot where a woman was stabbed to death. pic.twitter.com/1TxhXSo6xW— Jonathan Bloom (@BloomTV) June 10, 2016
Police are bagging up evidence in the stabbing death of a female construction worker near 5th and Folsom. 2 arrests. pic.twitter.com/ABVUNfSKF9— Jonathan Bloom (@BloomTV) June 10, 2016