clean the flue and get it inspected, and find a new wife
Steel goes paramagnetic at 1400 F (-ish)...That fire must have really taken off. One time I got distracted and came back after I heard my magnetic thermometer fall off the flue onto the top of the stove. But I think it was only up to 700 when that happened. I didn't even know heat could demagnetize steel.
My wife basically said, "Hey dummy pay better attention next time." I may have to look into these audible temp alarms. In these years of permanent WFH and Zoom meetings, I have to start up a fire and then get on a Zoom meeting. I will tell my wife, "Hey, watch the fire, I have to get on a meeting.". And even with my headphones on I can hear the fire rumbling out of control from my office, so I run out to close the damper and babysit the flue temp. In reality, nobody should leave the fire unattended until it is at the right temperature and under control.