Lea Michele Pays Tribute to Late Glee Costars Naya Rivera and Cory Monteith

Lea Michele is paying tribute to her late Glee costars Naya Rivera and Cory Monteith.

On Monday, Rivera, 33, was confirmed dead by authorities five days after she disappeared during a lake trip with her young son. The discovery of her body came the same day that Monteith died seven years prior as a result of a “mixed drug toxicity” of heroin and alcohol. He was 31.

To commemorate the lives of her castmates, Michele, 33, shared black-and-white portraits of the actress and actor to her Instagram Story — first posting a photo of Rivera followed by a shot of Monteith, whom she was dating at the time of his death.

Michele also shared a group photo from Glee.

Before Monteith's death in 2013, he and Michele were in love and had discussed marriage, a source told PEOPLE at the time.

Michele is now married to Zandy Reich, with whom she is expecting her first child.

Years before her death, Rivera opened up about her relationship with Michele, saying that "rumors of our 'feud' was blown out of proportion," in her 2016 memoir Sorry Not Sorry: Dreams, Mistakes and Growing Up.

"One of the Glee writers once said that Lea and I were like two sides of the same battery and that about sums us up," Rivera wrote. "We are both strong willed and competitive — not just with each other but everyone — and that's not a good mixture."

Michele played the competitive Rachel Berry, who dreamed of performing on Broadway. Naya played Santana Lopez, a popular high school cheerleader who later became known as an LGTBQ trailblazer.

Just last year, Rivera spoke of her "current" relationship with Michele, sharing during an appearance on Watch What Happens Live with Andy Cohen that there was never any "beef" between them.

"I don't think there was like ever any beef," Rivera told Cohen after being asked if her liking Michele's engagement announcement was her calling a truce. "It's a good ring," Rivera said of Michele's sparkler.

Last week, Rivera was reported missing after an outing to Lake Piru in Ventura County, California. Rivera and her 4-year-old son Josey Dorsey — whom she shared with ex-husband Ryan Dorsey — rented a pontoon boat.

When the boat became overdue for return after its three-hour rental, staff found it at the north side of the lake, with Josey wearing a life jacket, sleeping alone on board. An adult life jacket, believed to be the one provided to Rivera, was still on the boat. One day later, police announced she was presumed dead, maintaining they considered her disappearance to be "a horrible accident."

During a news conference on Monday, Ventura County Sheriff Bill Ayub confirmed her death. "We are confident the body we found is that of Naya Rivera," he said.

"It has been an extremely difficult time for her family throughout this ordeal ... our hearts are with them and we share in their grief for Naya’s loss," said Ayub.

The sheriff added that there is no evidence of foul play or suicide.

"He and Naya swam in the lake together," Ayub said. "It was during that time that her son described being helped onto the boat by Naya. ... He told investigators he looked back and saw her disappear under the surface of the water."

Later, Ayub added, "We believe that she mustered enough energy to get her son back on the boat, but not enough to save herself."