It's hard to get people to talk individually about Antonio and Dawn Armstrong.

It's not "he" or "she" but "they" – almost instinctively.

It's because that's how the couple lived their life, as "we," relatives and friends said.

Antonio Armstrong, a Kashmere High School graduate who became a Texas A&M University All-American and briefly played in the NFL, led an entrepreneurial family of five that included his wife and three children.

The parents, both 42, were solid members of the community who operated a small chain of local fitness centers. He also was the assistant pastor at a Gulfton-area congregation where his mother presides.

That cohesion was shattered early Friday morning when the couple's teen son allegedly opened fire inside their southwest Houston townhouse.

Bullets flew and hit his mom and dad. She perished at the scene.

Antonio Armstrong died hours later after transport to Memorial Hermann Hospital in critical condition.

All day Friday, friends and admirers expressed grief and surprise on the personal Facebook pages of Antonio and Dawn Armstrong.

Loved ones started a growing memorial outside the couple's business headquarters in Bellaire with posters that read "Be Strong" and "Power of Prayer" amid bouquets of daisies and hydrangeas.

Dawn Armstrong's second cousins, Vaun Lee and Clifton Downing, visited the floral tribute outside that gym on Friday afternoon, and both described their lost loved ones as pillars of the community.

"Her and Antonio together, they were what they call a power couple – a power team. When they unified, they began to make things happen 20-odd years ago," Lee said. "They are the family that everyone wanted to be like."

Lee added that the pair were good parents who had "great" relationships with their offspring. According to public records and social media, the children include two sons, 16 and 20, and a younger daughter.

"They kept them busy and they supported them in everything that they did. There was not any mark that they missed with their children," Lee said. "There was nothing that even could possibly have justified this situation. This doesn't even make sense."

Downing, who calls his cousin "Dawn Renee," received the news early Friday via a phone call from his mother.

"We get together every year at Christmas time," he said. "They're just great people. They're the rocks of our family."

Houston police were sent to the 5300 block of Palmetto near Mapleridge around 1:30 a.m. Friday following reports of gunshots.

Jimmy Dodson, a Houston Police Department homicide investigator, said authorities were trying to piece together what sparked the gunfire. Officers found no forced entry at the home. Two of the couple's children, who were at home at the time of the shooting, were not hurt.

Dodson described the father as a "hard-working bread-winner" and said there appeared to be no friction in the household.

"It was kind of an all-American family," the investigator said. The teen was placed in juvenile custody.

The former college athlete was remembered fondly by R.C. Slocum, the head football coach at A&M from 1989 to 2002.

"Antonio was a special young man. He was an All-American and an outstanding player, but he was an even better person," Slocum said in a statement released Friday afternoon by the university. "He was such a positive influence on his teammates. He always had a great big smile and was a joy to coach."

Armstrong lettered for the Aggies from 1991 to 1994 and received Defensive Player of the Game honors in the 1994 Cotton Bowl.

Current A&M Head Football Coach Kevin Sumlin also sent condolences.

"Our thoughts and prayers are with Antonio Armstrong and his family, his old teammates and the entire Aggie family," he said in a statement. "Our strength coach Larry Jackson was a teammate of Antonio's and thought the world of him. This is a terrible tragedy and our hearts are broken."

Antonio Armstrong extended his experience as a professional athlete to his business and to the Internet. This month, he founded a personal YouTube channel – "Strong Talk" – and began posting brief personal empowerment speeches.

Words from his introductory video may offer comfort to those who are grieving now.

"Through the healing process, you are strengthened," he said. "Life is about being happy and I hope that through these talks, you can take your own personal pains – your own personal disappointments – and find strength in it so you can be the best you that you can be."

His final video was posted on his Facebook page around 11:30 p.m. Thursday, just about two hours before police were called to his residence.

The 54-second snippet offers these words of encouragement and hope: "Remember this: You can never allow your talent to take you some place that your character cannot keep you. ... We spend too much time looking in the rearview mirror instead of dealing with that large window that's in front of us."

He also reached out to high-school athletes who aspired to reach the big time, just as he did in the late 1980s and early 1990s at Kashmere.

The Chronicle covered Armstrong in February 2015 when he delivered his "Tournament of Life" speech to 90 Houston Independent School District student-athletes on national signing day.

The former linebacker was San Francisco's sixth-round pick in the 1995 NFL draft who watched his football life end and real life begin with a career-ending injury.

He signed to the National Football League's Miami Dolphins in October 1995 and appeared in four games that season. He played in the Canadian Football League from 1998 to 2001.

"Hard times can't stop you, because you've got a mind to think your way out of things," Armstrong told the youngsters.

The Armstrongs were pillars at Spirit and Life Kingdom Center in southwest Houston, where the church color is a sunny shade of yellow and is led by Antonio Armstrong's mother, Pastor Kay Shorter.

In an Facebook tribute on Mother's Day in May, he praised her for keeping him when she became pregnant as a young teen.

"My then 14-year-old mother SAW ME AS A LIFE AND NOT A CHOICE!!!" he wrote, after offering bullet points on some highlights of his 42 years and 18 years of marriage: "3 Children, Assistant Pastor, Entrepreneur, Community Leader, Mentor, Life Coach, Motivational Speaker, NFL Player, All American."The Armstrongs' family-run athletic, fitness and wellness company – 1st Class Training Inc. – has three locations in the Houston area

According to the web site, the couple's oldest son, 20-year-old Josh, was a front office worker for the business.

Dawn Renee Whitely Armstrong belongs to a family from Atchison, Kansas that moved to the Houston area when she was a young girl.

"Her parents raised her very well," Lee said. "She never had an unkind word to say to anybody. She saw the positive in every situation. She was very encouraging."

Dawn Armstrong's autopsy was completed Friday, according to a spokeswoman for the Harris County Institute of Forensic Sciences.

A cause and manner of death has not been released. The agency received a call about her husband's death around 6 p.m. Friday.

Funeral arrangements are pending, according to a news release issued late Friday from A&M Athletics.

Dale Lezon, Brian T. Smith and Mike Glenn contributed to this report.