SUSNET PARK, Brooklyn (PIX11) – Technicians were working on the faulty security cameras in the train stations the morning a gunman opened fire on the subway in Brooklyn last month, officials said in a Monday letter to Congress.

The NYPD and the Metropolitan Transit Authority had previously acknowledged the cameras at the 25th, 36th and 45th Street stations were down when the suspect, Frank James, allegedly shot 10 people on April 12. But police said reports the lack of cameras “delayed the manhunt” were “unfair and misleading.”

In the letter, MTA Chairman and Chief Executive Officer Janno Lieber said the cameras at the three train stations were not streaming because of a hardware and software malfunction in the communications room. The issue was first detected on April 7 when the staff discovered a problem with the room’s fanning unit, according to the letter.

The day before the attack, workers were setting up the new hardware when the live feeds stopped, the letter said.

“On the morning of Monday, April 11, as technicians were installing new communication hardware, the camera streaming failed,” Lieber wrote.

As technicians were fixing the live feeds on the morning of the attack, police evacuated the communications room to investigate the shooting, the letter said. The MTA cameras were back online April 13.

“On any given day, we have approximately 99% availability of our subway station security cameras,” Lieber wrote. “Our repair protocol is to fix the camera within 72 hours, and staff currently estimate compliance with this goal to be approximately 80% of the time.”

The letter said there are more than 10,000 security cameras in New York City’s 472 subway stations, including 600 alone on the N Line in Brooklyn where the subway attack occurred. The MTA added that it would need $1.3 billion to add and upgrade the city’s security systems.