CORONADO, Calif. -- Four people were found dead Sunday at a downtown Coronado condominium, where gunfire broke out just over two hours into the New Year, officials said.

A 911 call was placed from a mobile phone about 2:20 a.m. to report shots had been fired at a three-condo structure at 1020 Park Place, according to San Diego Sheriff's Lt. Larry Nesbit.

Coronado police officers responded to the 911 call found an adult male victim with an apparent gunshot wound lying in the doorway of the residence, he said.

Officers attempted to make contact with anyone inside the condo, but were unsuccessful, Nesbit said.

The small Coronado police department called in a sheriff's SWAT team, which used a robot to enter the building in case an active shooter remained inside. The robot searched the first floor and SWAT team members then entered and searched the second and third floors of the residence, Nesbit said.

The bodies of two men and a woman were found inside, Nesbit said. But he would not disclose the exact location inside the structure where the additional victims were found.

It was not known if there was a single weapon or if gunfire was exchanged, but sheriff's homicide detectives said there was no outstanding suspect was being sought in connection with the deaths.

Officials obtained a search warrant for the three-condo structure off Orange Avenue in the heart of the island city about 3 p.m., Nesbit said.

Due to the "extensive crime scene'', the investigation may last well into the night, Nesbit said.

The Coronado Police Department, Naval Criminal Investigative Services, and San Diego Sheriff's homicide detail and crime lab unit were participating in the investigation.

The victims' identities were not immediately released and were to be determined by the county Medical Examiner's Office.

“I think it’s absolutely shocking," said Coronado resident Michael Hancock. "From what’s coming out bit by bit, it’s shaking everybody.”

Sunday's suspected murder-suicide comes months after another mysterious death at the Coronado Speckles mansion grabbed national headlines.  In July, the naked body of 32-year-old Rebecca Zahou was found bound, hanging from the balcony of the historic mansion.

Investigators ruled Zahou's death a suicide.

“This past year has just been ‘A’ typical. It’s unusual for this community," said Greg Panawek, a long time Coronado resident.  “I think Coronado is still a very fine community, but it really saddens me that our neighbors are going through this type of turmoil.”