Céline Dion is coping with the loss of her beloved husband René Angélil, followed by the death of her brother just two days later. 

Céline Dion said her final goodbyes to husband René Angélil Friday.

Along with thousands of family, friends and fans, the singer honored her longtime manager and husband of 21 years at his 3 p.m. funeral in Montreal's Notre-Dame Basilica, the same parish in which they got married in 1994.

Dion and Angélil's three sons – René-Charles, 14, and 5-year-old twins Nelson and Eddy – walked alongside their widowed mother as she gripped their hands walking into the church.

Dion covered her face with a black veil as she marched toward her husband's casket with her children, looking solemn as she held on to lilies of the valley, which were also fastened to the ends of every pew.

As she reached her husband's casket, Dion placed the flowers on top of the casket as she made the sign of the cross. René-Charles also placed a pillow on the casket.

Angélil's grown son Patrick spoke first in French, followed by René-Charles' brief remarks in English.

"Fifteen years is not a long time for a son to get to know his father ... [but] you left me with enough good memories of you to share with my younger brothers. As they grow older, without you being around, I'll make sure to pass on what I've learned from you," he said.

"You are a tough act to follow ... Dad, I promise you here that we're all going to live up to your standards," René-Charles finished before leaving the altar and embracing his mother.

The full Catholic funeral included communion, which Dion and René-Charles received first. After they sat down, she gave her firstborn a tender rub on the back as the choir finished their French hymn. Later, attendees listened to a recording of Dion singing "Love Still Exists."

Just before the funeral Mass concluded, Dion and René-Charles held tight to one another as they went up to sign the register. Once back in her pew, Dion then received a small pillow with rings on it, which she removed and placed on her fingers.

Tears filled her eyes as she processed out, a French version of her singing "For You to Love Me Again" filling the basilica. Walking alongside the casket with other family members, she offered small smiles and nods to the mourners who clapped as the service ended, many also crying.

Once outside, the family stood on the church steps as darkness fell, a bell chiming as the casket was placed inside an awaiting hearse.

Before the service, fans and mourners flocked to the area in a crowd that one veteran local reporter said surpassed the throngs who gathered for a glimpse of the couple's 1994 wedding.

The basilica's doors opened at 2 p.m. as mourners began filing in, while fans and locals lined nearby streets in 27-degree weather, standing behind barricades to watch arrivals down the block and across the street, which was closed to regular traffic.

Inside, every seat was topped with a mini-pack of tissues and a program written primarily in French.

It reads in part: "According to his wishes, all of Céline's songs were chosen by René. Those include: "Trois Heures 20," "L'Amour Existe Encore" and "All the Way."

The back of the program featured a candid throwback shot of Dion and Angélil looking happy together.

It also included a heartfelt letter from Stéphane Laporte, the director of Dion's Las Vegas show.

"René doesn't demand respect. He does better than that, he offers it," he wrote. "Because the most respected man of show business is the one who respects others the most. His genius is to think of everything, to never forget anyone."

Laporte also spoke about the incredible bond Angélil shared with Dion.

"Never did one single love matter more in the world than that of René's for Céline," Laporte wrote. "And Céline’s for René. The lover is no longer. But the love is always there. In her. In his kids. In everything this man loved. His love is everywhere."

Angélil succumbed to a years-long battle with cancer last week, just two days before his 74th birthday, on which Dion's brother, Daniel, also died of cancer at the age of 59. Since tragedy struck, Dion has done her best to put on a brave face for their children.

Canadian flags are flying at half-mast on all government buildings, a rare and notable honor for the manager who is receiving a national funeral.

"The support we've received has been such a blessing," Dion, 47, told PEOPLE Thursday at her husband's public visitation, where she stayed into the night, receiving thousands who had come to pay their respects and offer condolences.

A music manager, Angélil met Dion when she was just 12 years old and helped launch her international stardom before, when she was 19, she revealed their relationship took a romantic turn.

For much more on Dion and Angélil's love story and how the singer is focusing on the couple's children, pick up the latest issue of PEOPLE, on newsstands Friday.

"I understand that my career was in a way his masterpiece, his song, his symphony. The idea of leaving it unfinished would have hurt him terribly," reads a quote from Dion on the program from Thursday's memorial service. "I realized that if he ever left us, I would have to continue without him, for him."

A memorial will be held in Angélil's home-away-from-home, Las Vegas, on Feb. 3 at the Caesars Palace Colosseum from 7:00 p.m. to 9:00 p.m.