The city comptroller is keeping a close eye on the city's child welfare agency. The latest example of that would be a letter he released Thursday examining child fatality numbers. However, the analysis sparked an intense debate between his office and City Hall. They spent much of the day fighting over how many children actually died on the city's watch over the summer. NY1's Courtney Gross filed the following report.

As the city's child welfare agency is under fire, the City Comptroller Scott Stringer piled on.

"The data does not lie," Stringer said. "These kids are being left in dangerous conditions. The agency is not stepping up its game and as a result more and more kids are being left in harm's way."

He released a letter on Thursday reviewing 3,700 high-priority child welfare cases from July through late September. During that time period, he claims 38 children died.

Ten of those fatalities were from families who had at least four prior child abuse complaints.

City Hall said the comptroller was completely wrong about the Administration for Children's Services, known as ACS.

"The comptroller released a report drawing inaccurate conclusions and misstating ACS policies," said Jill Kraus of ACS. "Four of those fatalities took place prior to 2014"

They say he was playing a numbers game and misconstruing the data. Four of those deaths they told us occurred before 2014.

In fact, for that time period, an ACS spokesperson gave us completely different numbers. A spokesperson said:  “A total of 26 child fatalities occurred during the three-month period. 10 were fatalities in families known to ACS at some time in the last 10 years, and 16 fatalities were in families not known to ACS in the last 10 years."

"I can't speak to why they drew the conclusions that they did, but I can say not all of them were accurate," Kraus said.

Even after the numbers discrepancy, Stringer's office was sticking with its story.

They point to other numbers they say they uncovered.

According to Stringer's office, 32 percent of the cases they analyzed did not have proper reviews by supervisors before the case was closed.

They also note in 22 percent of investigations, case workers did not have face-to-face contact with child within 24 hours of an abuse allegation.