An arbitrator has ordered D.C. police to rehire a 911 operator who was fired after officials alleged that she and other employees did not answer emergency calls reporting a fatal house fire last year.

The ruling reinstated civilian operator Betty Bibb, who had worked for 12 years at the 911 call center before Police Chief Charles H. Ramsey fired her last summer. In reversing the chief's decision, the arbitrator criticized the department's record-keeping and its investigation into the 911 response.

Bibb was among seven employees targeted by Ramsey for dismissal after the Jan. 15, 2003, fire in a Dupont Circle townhouse, which killed Christopher D. Smith, 24. Police said that the first three people who called 911 to report the fire were put on hold.

The case generated much controversy, with city officials initially denying that problems with 911 had delayed their response to the pre-dawn fire. After neighborhood activists challenged that assertion, officials acknowledged that significant lapses took place. They blamed the problems on workers, including Bibb, who were "unplugged," or not taking calls at the time of the fire.

Bibb is the first employee to win reinstatement, with back pay, following a recent ruling by arbitrator Abbot Kominers. She also is among police and civilian employees who are suing the city in federal court to win back their jobs, back pay and damages.

Her attorney, Ted Williams, said that the findings show that management was to blame for problems. "You cannot trust the 911 system as it is," Williams said. "This was no fault of the employees."

The arbitrator heard the case after union officials filed a grievance over the firing. Ramsey said officials are considering an appeal.

"The bottom line is that the phones weren't answered," Ramsey said. "As a result of that, a person died. That's neglect of duty."

The arbitrator's review was not the first outside inquiry to criticize record-keeping at the department's 911 center or question the investigation into emergency response.

Earlier, trial boards and hearing officers recommended that the civilian employees and officers, including a sergeant, be suspended or not punished, according to Williams. High-ranking police officials overruled those recommendations, and Ramsey ordered that the employees be fired.

It remains unclear what Bibb was doing when the first call came in about the fire, just before 6 a.m. Officials alleged that she had been "inactive," or not answering calls for too long a period of time during her shift. That included an eight-minute stretch when the first calls were reportedly arriving at the center and put on hold, officials said.

But officials never told operators that they could be terminated for "inactivity" and did not factor in Bibb's other duties, according to the arbitrator.

She could have been talking with a supervisor or helping a dispatcher, Kominers wrote, saying, "The agency failed . . . to prove what she was doing." Logs that track employee breaks were missing, he said.

Just after 6 a.m., Bibb took a call reporting the fire but had trouble transferring it to fire operators, the arbitrator found. Police operators take all incoming calls to the 911 center and then transfer ones about fires and medical emergencies to another set of operators. Only one fire department operator was working at the time of the fire.

Kominers noted that Bibb had no disciplinary record and was regarded as a good employee by her supervisors and colleagues.