Q: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Garry Shandling’s doctor is reportedly mystified as to why the beloved standup died — and his refusal to sign the death certificate has spurred the coroner’s office to investigate. 
  
 Shandling’s physician has “repeatedly refused” to sign the document because he believed the “Larry Sanders Show” creator — whom he hadn’t examined in more than a year — to be in fine physical condition, TMZ reported Saturday. 
  
 COMEDIANS, STARS SHARE MEMORIES OF GARRY SHANDLING 
  
 As a result, the Los Angeles County Coroner’s Office has subpoenaed the comedian’s medical records and collected blood work from the emergency room at St. John’s Health Center in Santa Monica, where Shandling was pronounced dead Thursday morning. 
  
 Garry Shandling, regarded as a legend by his comedy peers, died Thursday at 66. (Mario Anzuoni/REUTERS) 
  
 A request for comment from the coroner’s office was not immediately returned. 
  
 A source close to the comedian told the Daily News Thursday that the 66-year-old Shandling had suffered an apparently massive heart attack. 
  
 “It’s a shock,” the source said. “He seemed pretty healthy, took care of himself. There were no known heart issues at all in his history.” 
  
 The Emmy winner had experienced signs of failing health just one day earlier, consulting with a doctor pal about shortness of breath and aches, the gossip site previously reported. 
  
 The doc advised him to visit the ER if the symptoms continued. When they did Thursday morning, Shandling apparently ordered a car to drive him to the ER — but ultimately phoned 911 and collapsed mid-call. 
  
 Emergency workers reportedly arrived at 10:45 a.m. to find the car service waiting outside his home. 
  
 Shandling's physician has reportedly refused to sign his death certificate. (Phil McCarten/REUTERS) 
  
 Shandling had, in fact, cracked an eerie joke about health problems on a Jan. 20 episode of Jerry Seinfeld's "Comedians in Cars Getting Coffee" webseries. 
  
 “I had a hyper-parathyroid gland that was undiagnosed because the symptoms mirror the exact same symptoms that an older Jewish man would have,” he said. 
  
 “You know, lethargic; you get puffy, you get heavy. You kind of realize you want a divorce even though you’re not married.” 
  
 The drily witty comedian, considered a legend by his peers, was best known for the critically acclaimed “It’s Garry Shandling’s Show,” which ran on Showtime from 1986 to 1990, and “The Larry Sanders Show,” which HBO aired from 1992 to 1998. ||||| Garry Shandling Doctor Refuses to Sign Death Certificate Coroner Launches Investigation 
  
 EXCLUSIVE 
  
 Garry Shandling has been dead for nearly 48 hours, but his death certificate has not been signed, because we've learned his doctor refuses to do so. 
  
 Our sources say Garry's primary physician has repeatedly refused to sign because he has no idea how or why his patient died. The doctor says he hadn't seen Shandling in more than a year and as far as he knew Garry was in good heath. 
  
 The doctor's refusal to sign triggered an official death investigation by the L.A. County Coroner, who will now officially determine cause of death. 
  
 We're told the coroner's investigators have already taken blood work from the ER where Shandling was pronounced dead. The investigators have also subpoenaed records from the doctor. 
  
 As we reported, people familiar with the situation tell us Shandling died from a massive heart attack. |||||
A:
Legendary comedian Garry Shandling died Thursday morning, but his doctor has "repeatedly refused" to sign his death certificate, prompting an investigation by the Los Angeles County Coroner's Office, TMZ reports. The doctor hadn't seen Shandling in more than a year, believed him to be healthy, and can't figure out why he died. According to the New York Daily News, sources say Shandling died of a heart attack after experiencing aches and shortness of breath on Wednesday. “It’s a shock,” one source says. “He seemed pretty healthy, took care of himself. There were no known heart issues at all in his history.” The coroner's office will now have to determine Shandling's cause of death. It has subpoenaed his medical records and taken blood samples from the emergency room where the comedian was pronounced dead.