Early afternoon: James C. Nicola, the artistic director of the workshop, speaks to Mr. Larson by phone. Mr. Larson seems better.

Tuesday, Jan. 23

1 P.M.: Another 10-out-of-12 day. Technical rehearsals resume.

4 or 4:30 P.M.: In a phone conversation, Mr. Larson tells Mr. Nicola that doctors have told him he has a virus or a flu, and that he should stay home.

11 P.M. Rehearsals end.

About 11 P.M.: Mr. Larson is taken by a friend to the emergency room at St. Vincent's Hospital and Medical Center, at Seventh Avenue and West 11th Street in Greenwich Village, after complaining of ''not feeling right,'' a low-grade fever and chest pain. A triage nurse documents his chief complaint as ''right chest pain.''

The nurse notes that the patient describes the pain as possible heartburn and says he was seen at Cabrini for the same symptoms two nights earlier. The patient rates the severity of the pain at 7 on a scale of 10. The nurse classifies the case as urgent, but does not speak with a physician about the vital-sign readings.

Wednesday, Jan. 24

12:40 A.M.: Mr. Larson is seen by an emergency room physician. The physician notes that the patient complains of ''sharp inspiratory right-sided chest pain.'' A chest X-ray and electrocardiogram are ordered. The physician interprets the chest X-rays and EKG as normal. Mr. Larson's condition is diagnosed as viral syndrome and he is discharged in ''improved'' condition.

During the cab ride home, Mr. Larson complains of pain and tightness in the chest. ''Nothing has changed,'' he is reported to have said. He arrives home in the early morning hours. Later in the morning, a radiologist at St. Vincent's interprets the X-rays as essentially normal. He reports: ''Heart size is at upper limit of normal.'' He does not find any problem that requires a recall of the patient. A cardiologist reads the EKG and indicates a question of myocardial infarction, a heart attack. There is no evidence of any follow-up.

Mr. Larson tells his father he still has chest pain, pain in his lower back and low-grade fever.

7:30 P.M.: Mr. Larson, looking pale and exhausted, arrives at the theater.