Updated

A mother called 911 for help as she texted with her son, who was trapped inside the Pulse nightclub. A sister told a dispatcher that her 20-year-old brother also was trapped, in a bathroom at the gay club, and that "he said there were a lot of dead people."

People were texting, calling and video-chatting for help during the mass shooting of 49 people in June, and their loved ones frantically called police dispatchers in turn, according to numerous audio recordings of 911 calls released Tuesday by the Orange County Sheriff's Office.

The sheriff's office took overflow 911 calls when Orlando Police Department dispatchers were inundated during the worst mass shooting in modern U.S. history. The recordings show sheriff's dispatchers mostly got busy signals when they tried to transfer calls back to police.

The Orlando Police Department has yet to release its 911 calls. A dozen news media companies including The Associated Press are suing for access to these public records as well as the communications between gunman Omar Mateen and the Orlando Police Department, during which authorities say Mateen pledged allegiance to the Islamic State.

The media groups argue that the recordings will help the public evaluate the police response, but the city of Orlando claims the recordings are exempt under Florida public records law, and that the FBI insists releasing them may disrupt the ongoing investigation.

Mateen was killed by a police SWAT team after firing at the officers, ending a standoff that had lasted for more three hours. In addition to the fatalities, 53 club goers were hospitalized.

The sheriff's dispatchers sound calm and sympathetic on the 911 calls. They took down names and identifying traits or clothes, and told callers to tell their relatives or friends to stay in place until officers and deputies at the scene could rescue them.

"What I need him to do is just stay where he is and don't have him do anything or go anywhere until deputies or officers clear the area," a dispatcher told the mother who was texting her son in the bathroom, about 20 minutes after the shooting started. "Tell him to stay tight and just follow the officers and deputies' directions."

More than an hour and a half after the shooting started, one man called dispatchers a second time, clearly frustrated that his ex-girlfriend hadn't been rescued from a bathroom where she was trapped with almost 20 others, including two dead people.

"People are shot and dead ... Are you guys sending anybody there?" the man said. "They are all scared to death, and they all think they are going to die."

Another dispatcher urged a caller not to call or return a text from his friend, who had been shot three times and was hiding in a bathroom.

"Because if he has the phone ringing, making noise or something, we don't know anything about anything, so at this point, we don't want any noise around," the dispatcher said.

A neighbor also called, saying panicked patrons were banging on his door, pleading for shelter and hiding behind his car. It was one of the first 911 calls that night, and without knowing the extent of the attack, a dispatcher told him to keep his door locked.

"Gunshots were going crazy," said a patron who left the club right before the shooting started.