Curtis Hoback went to work in Kansas City on Wednesday morning with a plan to wander over to the Chiefs’ Super Bowl rally at nearby Union Station and shoot some photos.

A hobby photographer, Hoback walked there around noon and hung out near the intersection of Pershing and Kessler roads on the west side of Union Station.

“I was just down there mingling, and I was taking pictures mainly of people celebrating,” said Hoback, of Lenexa. “And I heard 15 to 20 shots, very rapid, like within two or three seconds.

“I thought it was firecrackers. And, you know, time sort of slowed down and it just seemed like maybe 30 seconds before the crowd realized what was going on, and then all of a sudden, you know, it’s like a stampede.”

On Thursday morning, Kansas City Police Chief Stacey Graves said two juveniles and one adult had been detained in the mass shooting, which she said was sparked by a dispute between several people. Twenty-three people were struck by gunfire, including Lisa Lopez-Galvan, who died. Half of the victims were under the age of 16, Graves said.

Hoback said that after the shooting, he made his way to the area and started taking photos of the chaotic scene.

Numerous photos show shooting victims being assisted by medical workers. One man is on his back, surrounded by four men — at least two of them law enforcement officers, one pressing on his abdomen. A crowd is gathered behind the nearby barricades, and two girls who are among the closest look on in disbelief.

In another photo, a distraught woman is on the ground holding a man’s head as another woman presses on his chest.

Hoback said the shooting occurred as the rally wrapped up.

“The action on the stage was pretty much over and the last speaker had been up and they basically said, ‘Thank you, Kansas City,’” he said. “People were just barely starting to clear out.”

He said he didn’t see the actual shooting.

“I was probably 100 feet away, but there were a thousand people between,” he said. “By the time I got there, there were what looked like people who had been at the parade who probably had medical training, and very shortly police and FBI and Homeland Security were all there very quickly.”

While watching the frenzied scene unfold, he said, a thought occurred to him.

“It seemed like there was a lack of planning for something like this,” he said, “only in that emergency vehicles were having a very difficult time getting to the scene because of pedestrians. In my mind, it seems like there would have been a path that’s kept 100% clear, and a route in and out.”

Graves said Wednesday that there was a massive police presence for the parade and rally. About 800 law enforcement officers were working Wednesday’s event, she said.

As he reflected Thursday on what he had witnessed, Hoback said he didn’t see how any bigger law enforcement presence could have prevented the tragedy whose aftermath he recorded.

“In that kind of crowd, you can have a thousand officers,” he said, “and still not stop it before it happens.”