The desperate 911 call of a mother cradling a teenage boy stabbed by her daughter's boyfriend has been released.

Robynn Davis begged the victim, identified as 17-year-old Lucas Cavanaugh not to die, as she urged police in Mount Pleasant, South Carolina, to hurry, saying the alleged attacker was still on the loose.

According to the recording, reported by ABC, Ms Davis can be heard saying: 'He's in the house, he's somewhere. He's my daughter's boyfriend.'

Scroll down for the audiotape of the 911 call

Lucas Cavanaugh, 17, was stabbed to death on Sunday night. The killer was allegedly the boyfriend of a girl whom the teenager had sent a Snapchat message

Matthew Fischer, 16, has been charged with murder over the fatal stabbing of classmate, 17-year-old Lucas Cavanaugh, on Sunday in Park West, South Carolina

She can be heard on the eight-minute tape reassuring the victim and pleading with him.

'Lucas, baby, please, oh God. Are you alive? Yes, you are. Please, please let's make it.

'He's got a pulse and he is breathing but he's completely unconscious. He has been stabbed right in his stomach,' she added to the 911 dispatcher.

An incident report released by police on Tuesday described how an officer responding to the scene found Cavanaugh lying in the middle of the street with a stomach wound and two women sitting near him.

The stabbing allegedly took place because a teenage girl's boyfriend was upset about a Snapchat message sent by the victim.

Matthew Joseph Fischer, 16, of Mount Pleasant was visiting his girlfriend's home in Park West near Charleston, South Carolina on Sunday when he saw a message from Cavanaugh on her iPod, detectives said.

The message was sent through Snapchat, a photo-and-text app on which messages are visible for only a brief time.

The message angered Fischer, according to an arrest affidavit. Officials have not released details about the content of the message.

'The defendant took the iPod and contacted the victim. Words were exchanged at which point the defendant told the victim 'Come over 'and 'I'll kill you man,' the affidavit said.

A desperate 911 call was released of the teenage girl's mother begging police to hurry as she tried to save the life of Lucas Cavanaugh (pictured)

Cavanaugh, of nearby Sullivans Islands, came to the girl's house, and the two fought, authorities said.

'During the altercation, the defendant produced a knife from his right pant pocket and proceeded to stab the victim in the torso, resulting in death,' the affidavit said.

One of the women brought the officer a knife and identified it as the weapon, according to the report.

The woman said a youth had come to her house with a bloody knife shortly after the incident, dropped the knife and run off.

Fischer was later arrested at the scene while sitting in his mother's car, authorities said. He was forced out of the car at gunpoint and taken into custody.

Fischer is charged as an adult with murder and possession of a knife. He was denied bond on Monday.

He and Cavanaugh attended Wando High School.

The teen's friends gathered on a local beach on Wednesday evening to bid farewell to their friend, releasing balloons and lanterns and covering his beloved car in flowers.

A celebration of life service is being held on Friday.

'This is just a tragedy for the entire Wando community and the families involved,' Fischer's attorney, Peter David Brown, said at the bond hearing, The Post and Courier reported.