His eyes hidden behind dark glasses, a policeman standing guard outside a station in southwestern Dallas said he'd prefer to stay on duty than take leave.
"When I go home I'll probably break down," he says, standing in his dark blue uniform and assault rifle outside the district station.
Three of his close colleagues were among five officers killed when a gunman opened fire on officers monitoring a parade in the city, held to protest against the killings of black men by police.
Now is not the time for grieving, he says. "You say your piece, and then you get back to it," he says of the importance of staying on the job.
The victims of suspected shooter Mican Johnson ranged from a rookie to a 20-year veteran, said the policeman, who declined to provide his name. Four policemen and one public transport security officer died.
Age, rank and training counted for nothing. "How can you train for an ambush?" he asked rhetorically. "You cannot. They're coming from the back of your head. That's untrainable."
Dallas was quiet the morning after the shooting, with 22 city blocks in the centre cordoned off in ghostly silence.
The occasional investigator crossed the street in the searing Texan heat, and the only cars on the streets showed flashing police lights.
Small yellow cones marked the location of pieces of evidence.
It will take days to clear the crime scene and for the centre of Dallas to return to normal. Attempts to park on the inside of the cordon were turned away.
An FBI official pushed part of the barricade aside to let an armoured car through.
Resident Julian Gamboa, 24, said he saw it coming.
"It almost felt like something is gonna happen where policemen are going to be slaughtered," he said.
Too many black people have been killed and murdered recently, he said.
"There's been a lot of chaos. No one really knows what to do or feel."
He closes his eyes tightly, breathes, and struggles to finish the last sentence.
At the memorial service, he stood with friends among hundreds in a city park, prayed, and cried.
The pain runs deep. Pastor Bryan Carter, who is black, said there is disbelief and shock in the community.
The ninth-largest city in the US was only slowly coming to terms with the previous day's events.
"Dallas, our home, is about to become famous again for all the wrong reasons," columnist Jacquielynn Floyd wrote in the Dallas Morning News, 50 years after president John F. Kennedy was shot dead in the city.
In a powerful sermon, pastor TD Jakes warned against letting resentments fester.
"The tragedy that we ignore today will be on our doorstep tomorrow," he told a crowd.
Standing next to him Mayor Mike Rawlings said "we have led the next generation down a vicious path", and called the hostility between parts of the black and white communities "the cancer of separatism".
Some of that anger was aired by members of the public on Friday.
"It's the beginning of a war," said Daniel McCullough, wearing a T-shirt bearing the Black Lives Matter slogan.
Black people have been treated like "cotton-picking slaves" until now, he said, and a violent response to attacks by the police was overdue.
"Keep your eyes open," he said, adding that conflict was going to get worse, "between us versus them and them versus us".
At the close of a day full of pain, it is the words of comfort from priests, politicians and police that gave some hope the rifts can be healed.
So did words like those of Marlen Esquivel, who took her nephews to the police station to say thank you.
"Some people out here don't appreciate" the efforts of officers to keep the peace, she said.
Flowers and toy animals adorned the bonnets and windshields of two of the police cars parked outside, as passing drivers honked, or stopped to take photos.
"You can be military, law enforcement, first responders - you can't be trained to lose loved ones," said the officer standing guard.
"That's not human instinct, it's unnatural."
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