Excerpts from foxnews.com:

Fifty-five-year-old Chicago FD Lieutenant Jan Tchoryk died while battling a blaze in a high-rise building on Chicago’s North Side, of hypertensive-arteriosclerotic cardiovascular disease, according to the autopsy results released by the Cook County medical examiner.

Three other firefighters were hurt in Wednesday’s blaze and taken to hospitals where their conditions were listed as fair to serious, and two civilians also were taken to hospitals in good condition.

The extra-alarm fire was ruled accidental and started after combustible material was placed too close to a heat-generating appliance.

Tchoryk was the second Chicago firefighter to die this week.