Massachusetts District 7 Fire Investigation Unit Training on Self Activation of Light Switches

Does a light switch that is found in the "ON" position post-fire mean that it was ON before the fire began?

Jeremiah Pratt, P.E. Electrical Engineer and Managing Partner of Genesis Forensics has been a Fire Fighter and EMT since 1994 and has served on the Massachusetts District 7 Fire Investigation Unit (FIU) since 2019. He was recently chosen as their Training Coordinator and each month offers a relevant topic to study and discuss with the team.

Electrical Activity Caused by Fire

The August training for the FIU included discussion on electrical activity caused by fire attack of a light switch during a fire. The team explored fire dynamics that could result in electrical activity on circuits that were in a pre-fire "OFF" state, reviewed the article "Preliminary Results of the Investigation into Self Actuation of Light Switches during FIre Exposure" published in the Winter '15 edition of the NY IAAI magazine, completed individual testing and participated in group discussion.

Mr. Pratt offered exploratory questions to encourage team members to consider many aspects of data to be used in any fire investigation, including evidence, interviews, fire patterns, fire dynamics, electrical activity, testing, among others.