48 Hours: Shelley’s Last Breath - Full timeline of Shelley Tyre's tragic case

48 Hours: Shelley’s Last Breath revisits the shocking death of an energetic and beloved middle school headmaster named Shelley Tyre. CBS News reported that Shelley's husband, David Swain, was convicted of murdering her and was sentenced to life in prison.

According to Oxygen True Crime, Shelley met David, a Rhode Island dive instructor, in the early 1990s during a boat trip. Three years later, they married, but the couple never had children together. However, Shelley became a caring stepmother to David's two children from his earlier marriage.

The headmaster died while scuba diving at Cooper Island on March 12, 1999. She and David entered the water as buddies but separated underwater. When David surfaced after 35 minutes, Shelley didn't return. Later, companion Christian Thwaites found her lifeless body face up on the ocean floor near the wreckage.

Continue reading more about Shelley’s Last Breath.

Shelley’s Last Breath: Full timeline of the trip that ended in Shelley's death

Before March 12, 1999

Shelley and her husband planned to sail and snorkel near Tortola in the Caribbean because they wanted to spend time together and enjoy the sunshine in March.

March 12, 1999

Shelley’s Last Breath revealed that the couple arranged a sailing trip in Tortola with another couple and their son. The group rented a sailboat and began a scenic journey across some of the region's most remarkable scuba diving locations.

The group travelled to Cooper Island to explore the Twin Wrecks. Shelley and David prepared to dive together as scuba buddies. Later, David informed the police that they were separated once they were underwater. While enjoying the scuba diving, David focused on capturing photos of sea life, and Shelley counted fish.

After 35 minutes, David surfaced and returned to the boat. He was not immediately concerned that Shelley had not come back. Their companion, Christian Thwaites, entered the water and soon made a disturbing discovery. He saw one of Shelley's fins upright on the ocean floor and then found Shelley herself, lying face up near the wreckage with her eyes open.

Christian surfaced in panic and then shouted for help. David quickly took the dinghy to reach him. Christian carried Shelley's body, and David tried to resuscitate her with CPR. His efforts failed, and he declared his wife dead.

Shelley’s Last Breath: What happened after the incident?

A scene from 48 Hours: Shelley’s Last Breath (Image via YouTube/@48 Hours)

2002

Oxygen True Crime mentioned that Richard and Lisa filed a wrongful death case in civil court against David, who had received $600,000 after his wife's death. The damaged scuba equipment later found on the ocean floor disturbed them, even though there were no witnesses or DNA evidence.

Investigation reports revealed that Shelley's snorkel had no mouthpiece, the strap of her mask was broken, the pin that should have held the strap was missing, and one of her fins was standing upright with its foot strap pulled back. This evidence suggested that she might have been forced out of it.

2007

David Swain was arrested on the murder warrant in November 2007.

2009

According to Oxygen True Crime, prosecutors alleged that David had been romantically involved with Mary Basler, citing testimony that David had spent quality time with her, kissing her and drinking wine with her. Despite his denial, the jury convicted him of murdering Shelley in 2009 and sentenced him to 25 years in jail.