Ignoring alarms led to the death of a skilled nursing facility resident on a ventilator, according to the trial of three New York healthcare professionals that began this week.

In their opening remarks, defense lawyers argued the staffers were suffering from “alarm fatigue” when Carmela Contrera, 81, a resident of the A. Holly Patterson Extended Care Facility, in Uniondale, NY, became disconnected from her respirator in 2015. Registered nurses Sijimole Reji and Annieamma Augustine and certified nursing aide Martine Morland  allegedly heard the alarms indicating the disconnection, but waited nine minutes to intervene, Newsday reported. There were 2,000-plus alerts in a 24-hour period when the situation occurred, likely causing alarm fatigue for the defendants, lawyers said.

The prosecution asserts the three staffers were talking at their station 40 feet away while Contrera suffocated. But lawyers for Reji, Augstine and Morland argued that the cause of death was ruled as septic shock.

The trio has pled not guilty to felony charges that include endangering the welfare of a vulnerable elderly person, criminally negligent homicide and falsifying business records.