| Name | John Marek |
| Agency | Chicago Fire Department |
| Rank | Engineer |
| Type of Firefighter | Career |
| Age Range | 51 to 55 |
| Sex | Male |
| Date of Birth | 0/0/0 |
| Date of Death | 4/18/1949 |
| Cause of Death | Stress/Overexertion |
| Nature of Death | Heart attack |
| Attribute of Death | [not applicable] |
| Type of Duty | Firehouse duties |
| Incident Name | N/A |
| Incident City | Chicago |
| Incident State | IL |
| Incident Date | 4/18/1949 |
| Incident Location | Firehouse |
| Incident Attribute | [Not applicable] |
On April 18, 1949, Chicago Fire Department Engineer John Marek suffered a fatal heart attack while on duty at the Engine 116 firehouse.
Citations:
“Fire Department Engineer Dies of Heart Attack,” Chicago Daily Tribune, April 19, 1949.