It happened on the Eastex Freeway near Laura Koppe Rd. in north Houston.
The cab driver -- 56-year-old David Houston -- was listed in fair condition Monday at Ben Taub General Hospital. He had surgery on both legs and his hip Saturday.
From her southside home, Houston's mother told us she doesn't have many answers about how her son could have rammed into the back of the 18-wheeler, but she says something must have happened to her son before the fatal collision with an 18-wheeler.
She says her son is not a careless driver, and she believes he may have passed out before the accident.
"No, it would have to be a blackout or something like that because he's not careless like that. So it has to be something like that, but it's not no carelessness," she said.
Houston's two passengers -- 84-year-old Dorothy Britton and 56-year-old Sandra Smart -- died in the crash. The Harris County Institute of Forensic Sciences says both died from multiple blunt force injuries.Houston, who works for METRO, would take them home from the Medical Center after dialysis treatments.
"All the people he's been driving around are calling in now, telling what a good driver he [was]," his mother said.
We've asked the Texas Department of Public Safety for Houston's driving record. His mother told us he has worked for METRO on and off for years.
Witnesses told police Houston was speeding prior to the accident Friday and weaving in and out of traffic. While the Houston Police Department and METRO police investigate, the victims' families hold on to memories and hope for answers soon.
Relatives of the two victims are making funeral arrangements for this week.
Britton's family remembers her as soft spoken, but always full of big, kind words.
"She was always a big part of family functions and we'd always see her. It's pretty sad," relative K.Z. Jenkins Jr. said.
Jenkins learned this weekend of the terrible accident that claimed Britton's life and the life of Smart on Friday. Britton's loved ones say they can't believe she is gone, but they are focusing on their family for now instead of the tragic circumstances surrounding her death.
"Just the sadness of going to miss her," Jenkins said.
Houston is charged with criminally negligent homicide. His bond was set at $100,000.Yellow Cab issued a statement Monday which read in part, "The Yellow Cab family was deeply saddened about the accident which resulted in the passing of two passengers and critical injuries to the independent contractor driver. Those affected and their families are in our prayers. Yellow Cab is cooperating with the authorities to fully investigate this accident."