I dumped my coffee out the window, grabbed the mic, and told Dispatch we were two blocks away as Conklin accelerated up the hill, then braked so that our car slewed across Fourth Street, blocking traffic.

We bolted from the car, Conklin yelling, “Lindsay, watch out. There could be secondary explosions!”

The air was opaque with roiling smoke, rank with burning rubber, plastic, and human flesh. I stopped running, wiped my sleeve across my stinging eyes, and fought against my gag reflex. I took in the hellish scene – and my hair literally lifted away from the back of my neck.

Market Street is a major artery. It should have been pulsing with commuter traffic, but instead it looked like Baghdad after a suicide bomb. People were screaming, running in circles, blinded by panic and a screen of smoky haze.

I called Chief Tracchio, reported that I was the first officer on the scene.

“What’s happening, Sergeant?”

I told him what I saw: five dead on the street, two more at the bus stop. “Unknown number of victims alive or dead, still in their cars,” I coughed into the phone.

“You okay, Boxer?”

“Yes, sir.”

I signed off as cruisers, fire rigs, and EMS units, their sirens whooping, streamed onto Market and formed a perimeter at Third and at Fifth, blocking off oncoming traffic. Moments later, the command vehicle rolled up, and the bomb squad, covered top to toe in gray protective suits, poured onto the debris field.

A bloodied woman of indeterminate age and race staggered toward me. I caught her as her knees buckled, and Conklin and I helped her to a gurney.

“I saw it,” the victim whispered. She pointed to a blackened hulk at the intersection. “That school bus was a bomb.”

“A school bus? Please, God, not kids!”