The Food and Drug Administration is investigating the death of an 8-day-old baby boy who died at the Washington Hospital Center last month after his incubator overheated, an FDA spokesman said yesterday.

The investigation is focusing on whether the baby's death was caused by a malfunction of the incubator, as reported by the D.C. Medical Examiner's office. But it could also answer whether human error was a factor in the June 21 death at the hospital, where some nurses assigned to the baby's ward have been suspended.

Hospital spokesman Jane Snyder acknowledged yesterday that "some nurses who worked in the ward where the baby, Taman Jackson, was being treated for severe jaundice have been suspended. But she refused to discuss the reasons for the suspension or to say how many hospital staff members were placed on leave.

FDA spokesman Bill Rados said investigators from the agency, which is responsible for the safety and reliability of medical devices, had visited the hospital on Monday and again yesterday to examine the incubator and determine for themselves whether it overheated because of a mechanical malfunction.

"The bureau will look at this thing very quickly, and within a day or two we should know what happened," Rados said. Normally, where human error is involved, Rados said, the problem "comes down to improper use or maintenance of equipment." But he cautioned that the FDA "regulates the product, not human error" and would have no authority to pursue possible mistakes by the hospital staff.

If the incubator is found to have malfunctioned, the FDA will recall the product or take other corrective action, Rados said.

Taman Jackson was born at home on June 13. He was admitted to the hospital center for jaundice treatment on June 19 and died there on June 21. Once discovered in the overheated incubator, the baby was taken out, resuscitated and kept alive for 18 hours before dying from massive pulmonary bleeding.

The bleeding, according to D.C. Deputy chief medical examiner Dr. Brian Blackbourne, began when the incubator temperature was elevated above what it should have been, causing the baby's temperature to rise also. As the baby's temperature rose, a condition similar to heat stroke, there was massive bleeding in the lungs that resulted in death.

Blackbourne said yesterday that D.C. Medical Examiner Dr. James Luke based his findings on the cause of death on various laboratory reports, including an examination of the incubator. In an interview last week, Blackbourne said the device had been tested by electricians at the hospital's request.

The FDA said it was examining the incubator, which it said was manufactured by Narco Scientific Air Shields, Inc., a Hatboro, Pa. firm, to determine the exact nature of the equipment malfunction, if any.

The incubator used for the Jackson baby, according to the FDA's Rados, is Norco's C-86 model. He said he was not familiar with all the specifics of the model but that most of the company's incubators are designed with a thermostat, registering to 103 degrees Fahrenheit, to regulate temperature and a warning device or sound alarm to indicate if the incubator should be cut off.

A final report should be ready on Monday, or Tuesday, Rados said.

At Narco, spokesman Frank Vitale said the temperature level on the firm's incubators "is entirely controlled by the medical staff." He said most of the company's incubator products are set up to provide some type of warning in the event of malfunction.