The cause of his sudden and unexpected passing is still being determined.
He was only 53.

The Shedd Aquarium and Lincoln Park Zoo have announced vaccine mandates for employees and volunteers.
The zoo’s staff and volunteers must be vaccinated against COVID-19 by Oct. 15. Ninety-seven percent of staff have already been fully vaccinated, officials said.

https://www.audacy.com/wbbm780/news/local/zoo-aquarium-to-require-staff-volunteers-to-get-vaccinated?fbclid=IwAR25DLebCsgy1UpltBrcN5W2V8cv_yRWP_RJGFBH9VGR8NHJuG6IKDWkwUM

That really sucks !!! He was a great man !!!! We put on the 5K and 10K runs for the Lincoln Park Zoo every summer !!