New York City's Department of Investigation says public maintenance workers ignored safety checks at several New York City Housing Authority units.

The department says an investigation into an apartment fire that killed two young children in the Claremont Village Butler Houses in April led to the discovery of systemic safety failures.

Investigators first found that witnesses did not hear smoke alarms at the time of the Butler Houses fire. They say a NYCHA worker visited the scene earlier that day and found a broken smoke detector -- then allegedly reported that the system was fine.

The inquiry found that 70 of the 114 units re-inspected by DOI had safety deficiencies despite being cleared by NYCHA workers. The investigation also found that smoke alarms were inaccurately reported as functional in 42 percent of the apartments.

NYCHA staffers also allegedly submitted false reports claiming to have performed safety checks when they did not.

Investigators say they made several recommendations to NYCHA proper safety checks.

Jean Weinberg, NYCHA's chief communication officer, released a statement in response that reads in part, "Safety is our top priority. It is simply unacceptable to put NYCHA residents at risk because of neglect or indifference."

NYCHA also says it has taken disciplinary action against the employees linked to the discrepancies.