Tsunami warning system. A tsunami warning system (TWS) is used to detect tsunamis in advance and issue warnings to prevent loss of life and damage. It is made up of two equally important components: a network of sensors to detect tsunamis and a communications infrastructure to issue timely alarms to permit evacuation of the coastal areas.
The law also requires nursing facilities to maintain medical records for each patient. The records must be kept for seven years after the patient is discharged from the facility. If the patient is a minor, the records must be kept for one year after the patient reaches the age of 18, but for at least seven years.
That depends on the hospital or clinic center that maintains it. City run hospitals retain the records a lifetime depending how often you use that particular facility. Private hospitals usually retain them from 3 to 5 yrs. Records in New York are kept for seven years, or for seven years  after the patient turns 18.