Chief Frank Stetson retired on October 2, 1920, after having started the Department on its way to modernization.

The drill school for companies which had been initiated by Chief Cook in 1903 at Station 10 was transferred to new Station 2 on the southeast comer of 4th Avenue and Battery Street upon its completion in 192 1. Included in this station was a new drill tower. Also included in the station was a modern motor repair shop for the new apparatus and an auditorium, with a stage, for official Fire Department ceremonies as well as social gatherings.

On August 12, 1922, Fire Marshal Bringhurst retired. Inspector Robert L. Laing was appointed to the vacated post. He had been with the Fire Marshal's Office since its inception in 1916; Each of the Inspectors was required to pass a written quiz monthly in order to remain in that higher rank. This kept the proficiency of all members quite high.

Several factors caused the fire loss statistics to soar despite the fire prevention measures taken. The activities of arsonists increased greatly in Seattle during the 1920s, taking the Inspectors away from their primary duties to investigate the crimes. Also, the increase in the use of gasoline during this period was a big factor. Uses of the highly volatile liquid spread so rapidly that fire ordinances to regulate its handling were slow to keep pace. Enforcement of these ordinances proved difficult with the product in so many households.

Use of gasoline increased in the fire service as well. The 1924 arrival in Seattle of four 1000 gallon‑per‑minute pumpers, eight 800 gallon‑per‑minute triple combination pumpers, and five city service ladder trucks, all from Seagrave, allowed the last of the horses to be retired. All first line apparatus became motorized when Truck Co. 11 in West Seattle received a motor city service truck handed down from Truck Co. 10 after one of the new rigs was installed there. Chief Stetson's proposed fleet of reserve motor apparatus was now well established.

Gasoline's darker nature was demonstrated on Halloween Night in 1925. The location was known as Seattle's Automobile Row centered around 11th Avenue and East Pike Street, where blocks of buildings served as new auto dealerships, parts distribution warehouses, and repair garages. That evening, gasoline vapors from the leaky tank of an auto in the basement of Miller & Norton Sales Company, one of the new car agencies at 1107 East Pine Street, were ignited by the flame of the building's boiler. Fire burned for some time, consuming oxygen and filling the three‑story masonry building with thick smoke. Shortly after 6:30 p.m. a tremendous backdraft occurred. The entire building was instantly engulfed in flames. The explosion shattered large showroom windows as far as two blocks away. Fire spread across the alley into the two-story brick Willys‑Overland‑Pacific agency at 1519 12th Avenue. Burning debris, which landed on its roof, ignited the two‑story warehouse and store of the Firestone Tire & Rubber Company at 1520 - 11th Avenue. Fire also entered the Expert Radiator, Fender, & Repair Company at 1524 ‑ 11th Avenue, the two‑story masonry Sands Motor Company which was a Studebaker agency at 1512 - 11th Avenue, and three‑story brick Gardner Motors at I 100 East Pike Street. All these buildings sustained heavy damage. The three‑story Ballou & Wright warehouse at 1517 ‑ 12th Avenue was damaged, but was protected by automatic sprinklers, which activated and helped to check the fire's spread. Heat damaged the Kelly Springfield Motor Company across the street at 1525 - 11th Avenue. Heat vulcanized the rubber inner tubes in the show windows of the Hewitt Tire Company. This Halloween also happened to be a Saturday. Revelers were nut and about In large numbers. The crowd of spectators that developed slowed the approach of incoming apparatus. Several hose lines burst during the course of operations which soaked and scattered parts of the crowd. Power lines fell on several streets. Six fire fighters were injured in the fight before the fire was "tapped out" at six minutes before 1:00 a.m. The first alarm was dispatched a 6:35 p.m., with a 2‑11 at 6:39 p.m., a 3‑11 at 6:55 p.m., and a special call for four more engine companies and the watertower at 7:01 p.m. The insured loss totaled $479,975.

At 4:18 a.m. the following Friday morning, November 6, a fire of unknown origin completely destroyed the Great Northern Railroad Dock at the foot of West Galer Street below Queen Anne Hill. Destroyed on the large pier was a long two‑story sheet‑metal‑clad warehouse used by the Northwest Magnesite Company. Also destroyed was the large, old six‑story wood‑frame grain elevator of the Centennial Mill Company, which collapsed under the onslaught of the flames. Narrow access to the pier from the landside caused this fire to be fought defensively, to keep it from extending until it was controlled. The fireboats "Duwamish" and "Snoqualmie" set up water curtains that protected the few nearby piers. The Railroad's switch engine locomotives moved many boxcars to safety until the fire forced their retreat. The fire was "tapped out" shortly before noon.

One of Seattle's long‑lived and best‑loved institutions got its start about this time. Captain Steve Sanislo, a kindly, mild‑mannered man from a West Seattle station who had been with the Seattle Fire Department since 1909, was extremely bothered by the children he had seen perish in fires over the years. During the 1920s he developed a program about fire safety for children and, on his time off, he appeared before grammar school classes to present his act. The kids loved him! Each year he reached more and more children. Eventually Chief Mantor was able to obtain a budgeted position for him to work full time on his school program. Captain Sanislo continued to present his programs until his retirement in the mid‑ 19 50s. Many of today's adults can recall the Captain as their earliest and most vivid recollection of contact with the Seattle Fire Department. The number of persons alive now because they had recalled his much‑stressed "keep the bedroom door closed!" advice cannot be tallied. His work has been carried on with the creation of the Public Education Section of the Fire Marshal's Office. Today's programs are created and presented by Inspector Jim Sherman, one of the editors of this book. But tribute must also be given to others who superbly handled the job over the years, such as Rick Friedt, and Rockne Copple with his hit performances as "Mr. Bumblesbee," and the artists who created the films and props. Captain Sanislo died March 20, 1962, but the work of this very dedicated fire fighter was honored when the Seattle Public Schools built a new facility at 1812 Southwest Myrtle Street, naming it the "Stephen E. Sanislo Elementary School."

A city's fire defenses have long been graded by the fire insurance industry's agency which has been known at various times as the National Board of Fire Underwriters, the American Insurance Association, or Insurance Services Organization. Such a survey conducted of Seattle in 1926 brought about the upgrading of this City from a Class III to a Class 11, the highest classification ever achieved by any jurisdiction under the Grading Schedule. The use of canvas salvage covers by the truck and squad companies at major fires had been instituted and expanded by Chief Mantor. As a result Seattle's fire losses, though the highest in the City's history to that date, did not climb at as high a rate as the national average. This was a factor in the Underwriter's 1926 reclassification.

The decade of the 1920s ended on a tragic note with the stock market collapse in October 1929, which precipitated the Great Depression. The end was especially tragic in Seattle when, at 5:01 a.m. on October 17, 1929, fire raced through the small "Portland Hotel" in the skid road area at 211‑1/2 ‑ 1st Avenue South. The fire was set using a flammable liquid in the 2nd floor hallway above a clothing store, which occupied the ground floor of the three-story brick building. Fire cut off the residents from the only stairway as it raced through both hotel floors. Nine occupants were rescued by ladder. Since the building was narrow and fairly small, the fire was quickly controlled. In its aftermath, however, seven inhabitants lay dead. Three of the nine rescued occupants died a short time later.