Simon Katz had no idea that the s’more passed to him Monday night at a Chatfield High School homecoming bonfire was made with peanut butter.

The 16-year-old junior, who was allergic to peanuts, took a bite, became ill, went into anaphylactic shock and died, his father, David, said Wednesday.

Simon had mistakenly eaten peanuts in the past, his father said in a phone interview, but “those incidents ended with an emergency room visit, some epinephrine and he was good to go.”

Simon became sick after eating the s’more, and his friends drove him home to get medicine.

“I put him in my car,” David Katz said, “and tried to get him to urgent care.”

The teenager went into shock during the six-minute drive, his father said, adding that he was administering epinephrine injections to Simon during the drive.

When they arrived at the urgent-care facility, his father gave him mouth-to-mouth resuscitation in the parking lot before personnel from the facility came out.

Chatfield is in the Jefferson County School District, which has no districtwide rules restricting peanuts at school events, said district spokeswoman Michelle Balch Lyng.

“At the end of the day, peanut rules in our experience in schools are pretty lax,” David Katz said. “School districts don’t want to tell people they can’t bring that in.”

Simon’s mother, Kyna Saam Katz, said on her Facebook page that she has tried to persuade school officials to make schools peanut-free since her son was in preschool.

“Oh, my God, if everyone could learn what anaphylaxis means with any severe allergy, it can be vomiting one second and shock the next. If you ever see this, call 911 immediately,” she said on her post.

Simon was a bass player in the band Boats Without Oars.

“We are absolutely heartbroken. Our bassist, Simon Katz, passed away last night from anaphylactic shock,” the band said Tuesday on its Facebook page. “Simon, you were the most charismatic and amazing kid. You made every show we ever played special. This band would be nothing without you and you made this what it is.”

Simon recently had become interested in theater programs, his father said. “That was the center of his life. He was a happy-go-lucky kid, self-confident, he liked to be funny, a class clown, a goofball.”

He planned to go to college in Chicago and major in theater and music, his mother said. “He was a great entertainer.”

The Jefferson County medical examiner’s office has completed an autopsy but is not ready to release a final report on the death, said Stacy Salmon, a coroner investigator.

Crisis-response teams are at Chatfield to help students, staffers and the community during this time, Lyng said.

Students at the school are distributing ribbons of Simon’s favorite color, yellow, and the school will hold a moment of silence at its homecoming football game Friday night, Lyng said.

A private memorial service is planned for 1 p.m. Thursday.

Tom McGhee: 303-954-1671, tmcghee@denverpost.com or @dpmcghee

This story has been updated to relfect that the memorial service planned for 1 p.m. Thursday is private, and not open to the public.

