— The North Carolina Department of Labor is investigating the recent death of a woman who drove a campus bus at North Carolina State University.

Joann Veronica Griggs Sewell, 50, of Raleigh, died Saturday, three days after her family says she was overcome by fumes on a Wolfline bus on N.C. State's Centennial Campus.

A man who called 911 on Dec. 14 said a bus driver told him she couldn't breathe and asked him to seek help. The man said the woman was still on her bus near the College of Engineering complex, and he urged paramedics to hurry.

Sewell worked for First Transit, a Cincinnati-based firm that contracts with N.C. State to provide bus services across its campuses.

Co-workers told Sewell's family that they heard her call twice to the bus dispatch center last Wednesday to complain of fumes on her bus, Sewell's daughter, Sherese Brown, said Thursday. Dispatchers told Sewell to continue with her route, Brown said.

Sewell was on the bus for about an hour before she stopped to ask the man to call 911, according to her daughter.

Brown said her mother often expressed concern about the quality of the buses used.

Sewell, who worked for First Transit for 12 years, suffered from asthma, diabetes and high blood pressure, her daughter said.

First Transit spokesman Timothy Stokes acknowledged that the North Carolina Division of Occupational Safety and Health was looking into Sewell's death, but he declined to discuss details of the case.

The company is "very saddened to hear of her passing," Stokes said. "Our thoughts go out to the family."

He said he hasn't heard of any students or others getting sick on a Wolfline bus that day.

N.C. State doesn't plan to investigate First Transit's handling of the situation, spokesman Matt Shipman said.

"It is the contractor’s responsibility to ensure the matter was handled appropriately, and we believe that the contractor is acting in good faith," Shipman said.

First Transit has no previous workplace safety violations in North Carolina, Department of Labor spokeswoman Dolores Quesenberry said.

Sewell's family is left waiting for answers and wondering if workplace conditions contributed to her death. "This is something we can't get back," her daughter, Sherese Brown said. "You only get one mother."

Editor's Note: A picture of another Wolfline bus driver was included with this story for a short time on Dec. 22. WRAL.com regrets and apologizes for that mistake.