Marco A. Alva, Sr. can’t wrap his mind around how his coworker, who he considered a brother, succumbed so quickly to COVID-19.

“He was a healthy person, a very strong guy,” Alva said in a phone interview from his home Thursday, where he is in isolation because he was in close quarters with Carlos Consuegra, 52, of Union City, who died Tuesday and tested positive for the coronavirus.

The two men worked at Newark airport for United Airlines; Consuegra, as a ramp service employee in Terminal B, and and Alva in Terminal C. But they spent all their downtime at work and a lot of free time together after work.

Consuegra showed Alva the ropes when he started at United, 12 years ago.

“He was a good worker,” Alva said. “If you didn’t know how to do something, he would teach you.”

The two would go out after work for a few beers and shots of Hennessy or grab something to eat. And, as a perk of the job, they traveled together -- to Consuegra’s home country, the Dominican Republic, as well as Peru and Colombia.

Consuegra loved to play softball and worked out regularly.

“He was a blessing to me from the first day I met him,” said Jose Colon, a fellow softball player, in a social media post, “always had a smile on his face, jokes for days and the most humble friend that I lost. (W)e played softball for many years and I don’t think I’ll ever play again because the last conversation that we had, he told me that we were going to play together again this year. ... I’m just heartbroken and devastated"

Consuegra was at work up until last Tuesday, March 17. “A coworker told him he didn’t look good,” Alva remembered. “And then he fell asleep on a company tug.”

Consuegra was sent home from work and he went to Trinitas Medical Center in Elizabeth, Alva said, where he passed out and then was diagnosed with an ear infection and sent home. He tried to go back to work the next day, since he didn’t have sick time, Alva said, but the company made him stay home for two days, per doctors orders. He never returned.

On Friday, Consuegra was having trouble breathing so his family called 911 and he was taken to Palisades Medical Center where he was given a test for COVID-19.

Alva last spoke to Consuegra on Sunday. “He told me, ‘I have the virus,’” Alva said, adding that Consuegra told him to let work know.

Without a positive test result, United didn’t notify employees, Alva said.

“Monday I spoke to his daughter and he had a fever, was weak and had shortness of breath,” Alva said. “When I was talking to him, he was coughing a lot.”

The family told Alva they probably wouldn’t have the COVID-19 test results until Wednesday. It’s unclear if they got them before Consuegra died Tuesday.

United sent out a memo to workers at Newark airport on Wednesday announcing Consuegra’s death.

“Carlos Consuegra’s passing is a loss for all of us. His team described him as their big brother, who would always take care of them. He was known for his dry sense of humor and always going to the gym,” according to the memo obtained by NJ Advance Media.

Consuegra, who began working for United in 2007, is survived by a wife, two children, three grandchildren, eight siblings and his parents, the company memo said.

A United spokesman told NJ Advance Media, “We are deeply saddened to learn of the passing of one of our employees at Newark Liberty International Airport. The thoughts of the entire United family are with his loved ones.”

United told employees, according to the memo, that it was working closely with it’s Corporate Medical Department, the Centers for Disease Control and local health authorities to keep employees protected against the virus.

“We know that Carlos was admitted to the hospital at the end of last week and then diagnosed with COVID-19 shortly after,” the memo says. “The spread of the virus is difficult to identify and it’s unknown where or how Carlos contracted the virus.”

United told workers it’s been taking additional precautions, such as deep cleaning and thoroughly sanitizing areas, increasing hand-sanitizer stations, providing disinfectant spray and making sure each bathroom has ample soap.

“They said, ‘we deep cleaned.’ But you can tell if a place has been cleaned. You can smell it,” said Virgilo Dominicci, a ramp agent who was working in Terminal B Thursday night.

He doesn’t think United is being transparent with its employees, Dominicci said.

Consuegra’s belongings are also still in his locker. And if Dominicci -- who saw Consuegra on his last day at work -- wants to isolate, because he fears that he was exposed, he would have to use sick or vacation days, he says he was told.

“This isn’t a safe environment,” he said.

Alva, who, like Consuegra, is 52 years old, said he’s worried about his own health. He called his doctor to see if he could get tested but was told he has to wait until he develops symptoms.

“He told me to stay put and don’t be scared,” Alva said. “But I can’t stop being scared because I lost someone.”

He’s also scared for his coworkers, who he described as a “wolf pack.” United sent home 12 workers from Terminal B because they may have been exposed to the virus, Alva said.

“Like I always tell my friends at work, we are a family away from home,” he said. “Losing one is bad enough. Losing more would be devastating to me.”

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Allison Pries may be reached at apries@njadvancemedia.com. Follow her on Twitter @AllisonPries. Find NJ.com on Facebook.