UPS ACARS messages
I have no inside knowledge, but would venture a good guess that the readings sent to UPS HQ via datalink are probably fire/smoke detector signals, and from the sound they knew which sensor first sounded the alarm, so they can backtrack from there.
I mean, any fire detection system worth it's salt doesn't just yell fire, it yell's fire because sensor X yelled fire. Helps you get there quick.
G