A view from the rear of the Mitsubishi Galant involved in the Dayton, OH incident, looking forward, shows crush damage on the driver's side. The victim being worked on had his feet crushed in the reat footwell area behind the driver's seat. The airbag diagnostic unit is on the driveshaft hump to the left of the passenger's seat.
A close-up of the airbag diagnostic unit shows the cover crushed by spreader tips. Note the large-size electrical wiring serving the unit. With the cover removed, the circuitry that remained energized is visible.
The University of Extrication series covers three basic aspects of vehicle rescue training; vehicle "New Technology," extrication tool and equipment review, and practical skills evolutions.
Subject: Univeristy of Extrication (U/E) serires
Topic: Introduction and orientation to series
Objective: Understand scope of series
Task: Organize three-ring binder to compile training series (from print edition)
New Technology information includes important updates on modern vehicle construction features, a look at new vehicle equipment and occupant safety features such as airbag restraint systems. The design, operating characteristics, and influence the new technology item has on modern-day vehicle rescue and extrication practices and procedures is explained.
Extrication tool and equipment review includes analysis of the newest and most innovative vehicle rescue tools and equipment currently available to rescue personnel. Get the inside scoop on what's hot and what's not before you invest for your department.
To keep current with the newest rescue techniques to use at accident scenes, practical skills evolution training will be featured. Many rescuers continue to perform older less efficient techniques. To improve vehicle rescue operations, detailed step-by-step procedures on new evolutions are presented in this University of Extrication series. This skills training allows rescue personnel the opportunity to improve their rescue scene efficiency and safety.
Each University of Extrication training lesson is presented in a convenient notebook page format for the convenience of department training officers. Each page is marked with a large index letter for ease of filing. A standard heading at the top of each front page serves as a quick reference guide to the content of that lesson. This series is designed for easy indexing by the department Training Officer in a three-ring binder.
The Desired Learning Outcome for participants in this series is:
1. Have a working knowledge if the various designs, locations, functions and safety hazards presented by "new technology" items;
2. Review new extrication tools and equipment applicable for incorporating into the department's rescue inventory;
3. Understand new practical skills techniques that can improve the department's rescue scene efficiency and personnel safety.
Task: Organize three-ring binder to compile training series.
Airbag Restraint System
During what has become the most widely known vehicle extrication incident of modern day, two Dayton, OH, firefighters were injured when the dual airbags on a 1994 Mitsubishi Galant automobile they were working on deployed. Both firefighters, Tom Trimbach and Jim Kohler, were struck by the airbags with Trimbach being literally thrown through the air by the inflation force of the bag. Lessons learned from this August 1995 response reinforce the need for fire and rescue personnel to shut down the electrical system of any vehicle they perform extrication operations on at an accident scene and to "safety" the electrical cables and contact points.
District Chief Jim Beach, incident commander in Dayton, commented, "We were aware that the electrical system (of the Mitsubishi) was intact. We didn't feel at the time that it was necessary to disconnect the electrical system. Our prime concern was the possible hazard of fire. We weren't looking for airbags at that time."
In situations such as Dayton, where rescuers have people trapped and encounter a 'loaded' air bag system that has not deployed, action must be quickly taken to control the vehicle's electrical system. Here is a quick checklist for 'loaded' air bag system management at an accident scene:
- Stabilize scene hazards: fire, fuel, wires down, hazmat, etc.
- Stabilize vehicle to prevent movement; block and chock.
- If safe to do so, utilize vehicle's electrical controls to:
- Take away electrical power by disconnecting or cutting negative ground cable near battery. This allows airbag system electrical storage capacitors to begin their "drain" down.
- Secure end of cable with duct or electrical tape to prevent re-establishing contact with any metal components.
- Remain clear of the inflation zone of each air bag if it were to deploy (Electrical storage capacitors present in an air bag system may allow the system to remain energized with reserve power from four seconds to over 20 minutes even though the battery has been disconnected.)
- Proceed with normal rescue and EMS activities.
The electrical system of the damaged vehicle should be shut down early in the extrication process. If rescuers disconnect or cut battery cables, exposed metal ends can potentially touch another metal component and re-establish an electrical circuit accidentally. Crucial to the procedure of shutting down a vehicle's electrical system is using electrical tape or duct tape to cover the fresh cut ends of the cable, insulating the exposed metal. Another technique is to cut out and remove a complete section of the battery cable leaving two short, stubby ends that cannot move to contact any other metal objects.
Safety considerations include reminding fire, rescue and EMS personnel that not all airbag restraint systems operate with electrical current to activate the deployment mechanisms. Mechanical airbag deployment systems found frequently on modern-day vehicles do not require electricity to function and remain a possible deployment concern throughout the entire extrication operation.
Awareness of component parts of an airbag system discovered inside a vehicle during rescue operations is important. Respect for the sensitive nature of these systems is also key to insuring rescuer safety at the accident scene. Dayton Rescue One Firefighter Tom Trimbach, who actually crushed the airbag sensor unit during the extrication effort, adds "There is no standardization to the SRS (airbag) units or the deactivation of those units. I think there is probably certain things we can do for all the vehicles. One of them is to disconnect the battery cables, both battery cables. That seems imperative in the training we've learned since the accident. Both cables need to be removed from the battery."
Trimbach also advises rescuers, "Another thing I've learned personally is at the time I saw the metal box on the console (of the Mitsubishi) it really didn't look unusual. Being placed in the position it was, it didn't seem to be anything real critical to be concerned with other than a wiring harness.
But if you look at it now...it's an unusual looking box with some heavy duty bright red wiring you don't normally see in a vehicle. And anything unusual from here on is going to get a little bit extra attention from me. That I think is probably the biggest lesson I learned. If it looks unusual it probably is unusual and it takes a little more caution if you're going to deal with that area."
Task: List procedures used by your department to safely shut down electrical power to an airbag system of a vehicle.
A 30-minute video documentary on the Dayton, OH, airbag incident is available from the Fire & Emergency Television Network (FETN). This exceptional training program contains interviews with responders involved in the incident and shows graphic video footage of the actual airbag deployment as shot by a local new media cameraman at the scene. Please contact FETN for further information on the Dayton airbag incident at: Carroll McCurry, regional manager, FETN, 800-955-6655, ext. 5270.