The nephew of an elderly man who died at Tobey Hospital in 2008 is suing the hospital and a registered nurse for the man's "untimely death" after the nurse failed to ask for help with the "challenging" patient and failed to address the weak battery on his electronic heart monitor, which later stopped working, according to court documents.

The patient, 87-year-old Edward Harrigan, was found unresponsive on September 22, 2008 two hours after the monitor's battery stopped working, according to court documents.

"Mr. Harrigan's family informs me that they were told he died of natural causes and were never made aware of the actual circumstances of his death," Attorney Kenneth M. Levine wrote in an April 2011 letter to Southcoast Hospitals.

Levine said the hospital failed to "fully and honestly" inform the family of the circumstances of the death, violating a Massachusetts General Law which prohibits unfair and deceptive acts and practices. He asked that the family be paid $500,000.

Apparently after having not reached an agreement with the hospital group, Levine filed a medical malpractice lawsuit in U.S. District Court on September 20. The lawsuit names registered nurse Susan Spaulding, who was in charge of Harrigan's care, and Tobey Hospital as defendants.

Both Tobey Hospital and the U.S. Department of Health and Human Services launched separate investigations into the death in October 2009. Both investigations indicated that Harrigan's death "was the result of medical errors made by Susan Spaulding, R.N. and the agents, assigns and employees of the Tobey Hospital," according to court documents.

Levine, who represents the administrator of the estate - Harrigan's nephew David Harrigan II - wrote in the April letter that the family only learned of the circumstances of the death after a newspaper reporter received a Department of Health and Human Services report regarding the incident.

It is unclear why Harrigan was hospitalized.

Levine could not immediately be reached for comment and further information.

“When an incident such as this occurs at one of our hospitals it is distressing for all of us at Southcoast," Stephanie Lynn Poyant, Public Information Officer for Southcoast Health System, wrote in an e-mailed statement. "We assure you that the actions that were taken in 2008 following this incident, and that continue to be practiced at our hospitals today, have led to improved safety for our patients. Southcoast has since been recognized as one of the leading hospitals in the U.S. for patient safety."

Poyant also wrote that though the hospital learned of the lawsuit through media reports, it had not yet been served. She declined to comment further about the case citing hospital privacy regulations and "respect for our employee's privacy."

We update this story as more information becomes available.