Fire Investigation - Assignment Example

Assignment briefing Name: Date: University Affiliation Assignment briefing INTORDUCTION Fire is one of the main hazards Affecting human life where there is loss of property, lives and also permanent body injuries or disabilities. Appropriate fire fighting systems are required to help counter this threat in the society. Incase if a fire accident a carefully conducted intelligent investigation system needs to be conducted. This will help provide the correct findings on what was the actual cause of the fire and how can such a situation be avoided. The investigators will need to use indicators such as heat horizon of a building or smoke horizon to be able to tell where the fire originated from and where it headed to. (John 2000) 1. With reference to the fire investigation books explain the distinction between a smoke horizon and a heat horizon. And explain how the two horizons could be evaluated. What could interfere with the horizon and would be a help or hindrance to the investigation. a. Smoke horizon This refers to the highest lying layer of smoke caused by temperature inversion. From observing at the earth’s point one see it as a clear horizon in the sky. In order for such a scenario to occur smoke in real sense has usually covered the real horizon. (Bryan, J. 1995). Figure 1: image of a smoke horizon In cases where minimum heat impact on the surface can be seen the deposits on its surface can help to easily know to what extent the walls have been stained. This in turn helps to know the nature of the fire as well as to what extent it caused damage. Smoke horizon levels in most cases do vary with ventilation sources hence can be very useful in determining which ventilations and windows were open during the fire. It also will be important in determining what caused the deaths in the fire accident. Some of the important parameters which are usually checked when studying smoke horizon are: air quality where a special sensor is used to determine the amount of foreign material in the air. The results are useful in determining the extent to which the air quality has changed in the atmosphere of measurement. Compliance law monitoring: ensures the public areas space is polluted to the least required levels. Some of the questions being asked in this process are the laws set in place being effectively implemented. Assessment of the smoke horizon economically is done by checking how many employment opportunities it creates versus the negative impacts it brings along (Bryan, J. 1995). Heat horizon This is a Low lying heated air level that fills the atmosphere caused as a result of temperature difference. This makes the heated air to cover he real horizon producing an appearance of heat waves reflection. (Bryan, J. 1995). Figure 2: image of a heat horizon Whenever at any given place hot air is directed over a space due to buoyancy force the air rises upward and is made to flow outwards on a surface. During the flow of such gases on a surface flame font makes an angle which is acute angled to the surface over which air flows. When this flame meets a vertical surface some specific font will be generated that will help tell its direction. Further accumulation of the hot gases will lead to generation of a hot gas layer. Which will gradually fill the room and the excess spill over to the next room through windows? This further leads to the formation of a stair step like pattern since the origin room or space tends to have more concentration than the other regions as a result it can be used to guide the investigators on the direction of fire. This is made possible as it easily allows them to be able to trace the flow of fire. One of the common methods used to evaluate heat horizon is by use of mathematical temperatures models. The second way of evaluation is the extent of effect to agriculture output at high heat waves crops are damaged lowering the fields output. Economic and social impact assessment provides another way of assessment. At high heat waves ranges minimum interaction of people compared to when the ranges are lower. (Bryan, J. 1995). 2. What is a chain of evidence and why is it important in a fire investigation This is a collection of proof that can be used to decide whether a given case was valid or not. There are various cases that can be considered to be evidence reliable for a given fire investigation case ( Proulx , G. 1995). Can also be defined as a documentation of a physical activity that has taken place. Chain of evidence helps to fully justify the cause of a fire in any fire accident under investigation. There are different types of evidence which include: direct evidence this type involves evidence that is obtained by use of any of the five senses of human being. They are sense of smell, sense of sight, sense of taste, sense of sound and sense of smell: indirect evidence: only meant to support certain elements in an investigation as they cannot proof anything on their own. The third type of evidence is the physical/real evidence: such type of proof do not need any explanation at all by looking at what you have at hand you can clearly tell what happened without any doubt. (Proulx, G. 1995). Examples of evidence include, DNA testing samples, video recorded taken during and after the crime scene,. When using or collecting a chain of evidence there are five important things which one will have to keep in mind. Collected evidence should have been done in a legal way , well recorded and stored. The chain of evidence should be as precise as possible with founder reference .Whenever it’s given to someone else it should always be signed for. (Proulx, G. 1995 ). 3. How could it be possible that a room with two apparent sources of ignition could possibly not be the work of an arsonist? An arsonist refers to a kind of person who deliberately sets out a fire with evil motive or intensions to destroy property or life. A motive is usually the proof the fire was caused by an arsonist. (Horasan et al 1994) In case a fire is caused by an arsonist a burning material or accelerator is used in most cases to ensure the fire burns extraordinarily destroying property within a very short period of time a good arsonist who has planned to destroy some property by fire will make the fire to originate from the bottom floor so that it can have many causalities rather having it in the middle or top floors of the building (Horasan et al 1994) Use of flammable ignition sources such as diesel or petrol can be used to conclude the fire was caused by an arsonist. If it can occur that a fire has occurred with no accelerator trails then it can be concluded that the fire was not caused by an arsonist. This is simply because arsonists have intentions of mass destruction hence they will use the available accelerator at their disposal to ensure that the fire does enough damage before it’s contained. Hence arsonists will find an accelerator a very important component it archiving his/her goals of destruction by flames (Horasan et al 1994) 4. The fire investigation text book “scientific investigation of fire investigation” second edition by john letini contains many case studies in which the author has given a second opinion about the origin and cause of fire. Pick any of these cases and write a critic giving emphasis on the examples of errors and poor decision making by the original fire investigators. The case study that I took was the which first investigation team claimed the fire was caused by an arsonist attack where gasoline found at the back of an old car in the backyard was used as the accelerant to fire. These results were found to be obviously wrong compared to reality and it was decided a new investigation team redo the investigation. The following were some of the flaws from the first investigation as discussed below. The results of the first investigation team were that the fire was an arsonist attack. Gasoline had been used as the fire accelerator according to this team. The accelerator was hidden at the back of a broken down car. After critical looking at the evidence presented by the team the panel with no doubt easily rejected the results as they did not make sense at all, had so many questions which needed to be answered. (John 2000) The first weird thing was the hiding of gasoline claimed to be used as an accelerator at the back of a car that had broken down. It was a kind of careless behavior from the so called arson because why wouldn’t he not hide the accelerator in a safer place where people cannot easily get to it. Simply because when investigating the team would straight away go to any stationary vehicles in the vicinity and one of the first places to be checked would be the boot of the car and that’s where the investigators claimed the jag of gasoline was found. (John 2000) The other issue which arose was that the constitution of gasoline claimed to have been used by the arsonist, was the same as the gasoline which had been place in the car was found to be of same type as the one found in the mower which was operational a day before the incident. Could it be a possibility the gardener had decided to put the gasoline in the old car so that it could be used in future days to operate the mower engine. This led to raining of eyebrows over credibility of the work done by the first team (John 2000) The other weird thing about the results of the first group of investigations is that they found some part of gasoline claimed to have been used as an accelerant in the jag. The main essence of using an accelerant is to increase the rate at which the fire spreads so why would someone just use a small portion of the gasoline and leave the rest that’s reducing the effect of the fire. It also does not make any sense to see that the claimed arsonist could easily give away the evidence of the accelerator used. Since the jug with gasoline was left at a position no smart arsonist would do because they would prefer to keep the evidence of using such an accelerator away from the investigators as much as possible. The above cases are some of the examples which helped to nullify the results of the first investigation team and bring in a new one on the same fire accident... (John 2000) CONCLUSSION Proper fire investigations will always give the correct realistic findings on the cause of the fire . most people who would opt to do shallow investigations at the end of the day provide the client with wrong information on what caused the fire, if it was an arsonist attack, any accelerant used or it was something that came accidentally maybe due to accidental electricity faults. Studying of heat and smoke horizons helps to easily guide the investigation team in a reliable way the origin of the fire and where it was headed to the damage caused. Hence proper fire investigation is very key in helping avoid such fire accidents in the future. (John 2000) REFERENCE 1. Brennan, P. (1997). ‘evaluation of smoke horizon , Proceedings of the Fifth International Symposium, Yuji Hasemi (ed.), World Congress Centre, Melbourne, Australia. 2. Bryan, J. (1995). ‘Behavioral responsein fire investigation ’, SFPE Handbook of Fire Protection and investigation Engineering, 2nd edn. 3. Bryan, J. L. (1983). ‘An Examination and Analysis of the Dynamics of the Human Behavior’, the MGM Grand Hotel Fire, NFPA, Quincy, MA., USA. 4. Fahy, R. & Proulx, G. (1997). ‘smoke and heat horizon evaluation’, Fire investigation Science: Proceedings of the Fifth International Symposium, Yuji Hasemi (ed.), World Congress Centre, Melbourne, Australia 713–24. 5. Horasan, M. & Bruck, D. (1994). ‘Investigation of causes of fire”, 4th International Symposium on Fire Safety and investigation Science Proceedings, ISFPA, Gaithersburg, MD, USA 715–26. 6. john letini (2000) “scientific investigation of fire investigation” second edition, ISFPA by pages 76-79 7. Jones B. K. & Hewitt A. J. (1986). ‘Leadership and Group Formation in High Rise Building Evacuations’, Fire Safety Science: Proceedings of the First International Symposium, Hemisphere Publishing Corp. Washington,DC, USA 513–22. 8. Pauls, J. (1996). ‘Evidence analysis , SFPE Handbook of Fire investigation, 2nd edn, National Fire Protection Association, Quincy, MA.,USA. 9. Proulx, G. (1995). ‘Evidence obtaining and evaluation in fire incidents buildings’, Fire Safety Journal, 24 (3), 229–46. Read More