The attorney for the woman whose husband was killed in a vehicle crash with Venus Williams said the family will file a lawsuit against the tennis star.
A report obtained by Reuters said the other driver, Linda Barson, 68, saw her passenger Jerome Barson, 78 injured in the accident and taken to the Florida trauma center.
Witnesses reportedly said she was driving her SUV through a red light at the intersection and into Mrs Barson's saloon auto.
No charges have been filed against Williams, but Palm Beach Gardens Police said the crash is still under investigation. There is no mention in the report of Williams being cited.
Williams's attorney, Malcolm Cunningham, did not directly address the accident report's finding that his client was at fault, but said the tennis star was not issued "any citations or traffic violations".
Barson's wife Linda was driving with her husband in the passenger seat when she T-boned Williams' SUV after the athlete abruptly entered the intersection.
The Palm Beach County medical examiner's website shows that a Jerome Barson died on June 22. When that light turned green, Baron drove her 2016 Hyundai Accent into the intersection. She's in London preparing for Wimbledon, which she has won five times, the last coming in 2008.
The Barsons' vehicle was "crushed, the front windshield shattered, the airbags deployed, there was crush damage to the back on the motorist's side, and the back window was shattered", the lawsuit says.
His wife went to the hospital with broken bones and other injuries.
According to police reports, William's vehicle was traveling at 8km/h when the accident occurred and there were no drugs, alcohol or texting involved.
Michael Steinger, the attorney for Linda Barson, had no immediate comment.
On Friday evening, Williams broke her silence regarding the accident. Williams reportedly told police she had been attempting to make it through traffic while driving 5 miles per hour when she had to slow down, causing her SUV to block the right of way.