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The 1871 Chicago Fire ranks as the third largest fire loss in the US, behind the World Trade Center fires in 2001 and the San Francisco Earthquake and Fire in 1906. The Chicago Fire started late on Sunday, October 8, in or around a small barn bordering the alley behind 137 DeKoven Street. More than 250 people were killed, 100,000 were left homeless, 17,400 structures were destroyed, more than 2,000 acres burned and the result was $3.3 billion in property damage in 2013 dollars1While there is some doubt that Mrs. O’Leary’s cow actually started the fire, there is no doubt that a number of factors turned what could have been a small barn fire into a conflagration. More than two-thirds of the structures in Chicago were made of wood. 2 Most of the houses and buildings were topped with highly flammable tar or shingle roofs. Many sidewalks and roads were also wood. Making things worse, the city had only an inch of rain from July 4 to October 9, causing severe drought conditions. Further complicating things, strong winds from the southwest carried flying embers toward the heart of the city.

The Chicago Fire changed the way people thought about fire safety. Today, we are more aware of fire hazards. Two of the biggest game changers in fire prevention have been automatic sprinklers and smoke alarms.

Automatic sprinklers appear

It has been said that the first fire sprinkler was invented in the 15th century by Leonardo da Vinci. He was asked to build a “super-oven” for a patron who loved food and entertaining. Worried about the tremendous heat the oven generated, Leonardo da Vinci designed a system of conveyor belts – presumably with water buckets - to prevent a fire from occurring. According to some sources, “fire broke out and the sprinkler system worked all too well, causing a flood that washed away all the food and a good part of the kitchen.” 3

The first modern sprinkler system is credited to Henry S. Parmalee of New Haven, CT. He created and installed his fire sprinkler system in 1874, using solder that melted in a fire to plug holes in the otherwise open water pipes. His solder was part of the sprinkler itself. The sprinkler was connected to an opening in the pipe, very much like a modern sprinkler.

Fire sprinkler systems were first installed and used almost exclusively for the protection of commercial buildings, whose owners were generally able to recoup the cost of the systems with savings in insurance costs. As early as 1934, the National Board of Fire Underwriters required installing a sprinkler system when buildings wanted to increase their footprint beyond the limit set forth by its construction and occupancy.

Today, sprinklers are reliable and highly effective systems designed to activate early in a real fire. They respond to heat, not smoke. In a factory or warehouse, each sprinkler reacts only to the fire conditions in its area. While the fire department is on the way, sprinklers work quickly to help control and contain the fire. With an automatic sprinkler system, water release in a fire is generally much less than would occur if the owner of the building had to wait for the fire department to suppress the fire.

Properly designed sprinkler systems have become an essential element of warehouse fire protection. According to the National Fire Protection Association (NFPA), warehouse fires have declined substantially over the past 30 years. In the US and Canada, automatic sprinklers have become mandatory safety equipment in newly constructed hospitals, schools, hotels and other public buildings. Yet, sprinklers are still rare in stores and offices, public assembly properties and homes, where most fire deaths occur.

Enter smoke alarms During Fire Prevention Week (October 5-12), the National Fire Protection Association (NFPA) is promoting the use of smoke alarms in residential homes. Like automatic sprinklers, smoke alarms save lives.

As of 2013, it was estimated that smoke detectors were installed in about 93 percent of US homes and about 85 percent of UK homes.

One of the first automatic electric fire alarms was invented in 1890 by Francis Robbins Upton, an associate of Thomas Edison. In 1902, the first electrical heat detector and smoke detector was patented by George Andrew Darby in Birmingham, UK. In 1939, Swiss physicist Dr. Ernst Meili devised an ionization chamber device capable of detecting combustible gases in mines. He also invented a cold-cathode tube that could amplify the small electronic signal generated by the detection mechanism sufficient enough to activate an alarm. It took until 1951 before ionization smoke detectors were refined enough to be sold on the market in the US. Because of their high expense and large size, they were used in major commercial and industrial facilities.

The first affordable home smoke detector was invented by Duane D. Pearsall and Stanley Bennett Peterson in 1965. It featured a battery powered unit that could be easily installed and replaced. The first single-station smoke detector was invented in 1970 and was an ionization detector powered by a single 9-volt battery. These detectors cost about $125 each and were made available to the public in the early 70s. In 1976, the National Fire Protection Association (MFPA) issued the LifeSafety Code (NFPA 101), which required smoke alarms in homes. In 1985, smoke alarms were modified to reduce susceptibility to nuisance alarms. In 1993, the NFPA 72 required smoke alarms be placed in all bedrooms in new construction. By 1995, the 10-year lithium battery powered smoke alarm was invented and the NFPA began requiring replacement of smoke detectors after years in 1999. As of 2013, it was estimated that smoke detectors were installed in about 93 percent of US homes and about 85 percent of UK homes. A recent NFPA study “Total Cost of Fire in the United States” says that home fire deaths decreased by 53 percent between 1977 and 2013. The number of home fires also declined steadily during the same period, for an overall decrease of 49 percent.

Technology brings positive changes

Technology has made a huge impact on fire prevention and firefighting. Preventive equipment has evolved from automatic sprinkler systems and smoke alarms to include smart alarms, custom-tailored sprinklers, high pressure hoses, fire suppression suspension equipment and specialized systems, including aerosols and chemical agents. Commercial-use smoke detectors and fire alarms have become high tech. Smoke detectors can let you know if there is smoke. They can also let you know if the detector or alarm needs to be cleaned. They can alert you via text message or email. Some can alert the property owner of exactly which office or floor the fire is on. And, they can transmit the information directly to the Fire Chief’s iPod, in real-time. Another big advance has been building and fire codes that require fire protection features such as sprinkler systems, fire alarms and fire resistance-rated construction. Most commercial sites have to be inspected periodically to make sure they are being operated and maintained in a safe manner. Yet, home fire deaths - including those in one-and two-family homes - still accounts for 85 percent of all civilian fire deaths. And almost two-thirds of US home fire deaths resulted in homes with no smoke alarms or no working smoke alarms. It is estimated that about 30 percent of all installed alarms are not working due to aging, removal of batteries or failure of the owners to replace dead batteries. Obviously, more needs to be done to make sure homeowners have working smoke alarms in their homes.


1. Largest fire losses in the United States, National Fire Protection Association, September 2014.

2. Chicago Historical Society,

3. Gelb, Michael, “Think like Leonardo da Vinci: Seven Steps to Genius Everyday,” Delacorte Press, 1998. 4. “US Experience with Sprinklers,” National Fire Protection Association, June 2013.


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