State law required the Board of Fire Commissioners investigate every fire in which property had been destroyed within 2 days. They had full power to summon witnesses and take testimony under oath, and report to the city clerk, who in turn would report semi-annually to the State Insurance Commissioner. Investigations of fires were made by a fire department pensioner, assisted by the police.
As well as investigating fires, Chief French was an advocate of fire prevention. He believed that preventing fires was one of the prime duties of a fireman. It was over twenty years before the investigation and prevention became a full division of the department. On June 1, 1948, the Bureau of Fire Prevention was established with a Deputy Chief in charge. The Bureau continued as a one-man operation until December 4, 1961, when as assistant was added. This division currently has 5 personnel.
On July 30, 1927 the department suffered its worst accident in its history. Captain Frank H. Harvey and firefighter Louis A. Cote died as a result of a collision between Hose 1 and Ladder 3 at Union Street and Lake Avenue while responding to box 711. Six other firefighters were injured. Chief Charles French, along with the Board of Commissioners, conducted an investigation to determine its cause. When the investigation was concluded, the following statement was issued "It is our opinion that the accident was unfortunate and unavoidable and that the drivers should be exonerated from all blame."
Beginning in 1932, the Department began to feel the effects of the great depression. On December 17, 1931, the work hours were reduced to 112 hours per week with a 10 percent cut in pay. On August 8, 1932, the members returned to 126 hours per week. In March 1938, the member's hours were permanently reduced to 112 hours per week. Pay for sick leave was discontinued unless the fireman was injured in the "service".
When a water main broke in 1936 between West Manchester and St. Anselms College, old Engine 7 was called into service. The engine, manned by retired Captain Walter Morse, operated 24 hours a day for 9 days. It pumped water from a hydrant, up the street past the break, and into a second hydrant to supply water to the "hill". This feat showed the superior workmanship of the apparatus built during that era.
The war years did not leave the department completely unaffected. Beginning December 10, 1941, flags were flown every day. December 11, 1941, it was ordered that all off duty and call firefighters had to report for duty on air raid signals and over the next years several were received. Beginning May 4, 1942, the companies began a night watch, which was discontinued December 6, 1943. Other potential problems must have been anticipated as the companies were supplied with riot guns and cartridges until October 20, 1944. On March 9, 1943, the companies were issued non-combatant gas masks and further air raid orders. Several of the call men left to join the war effort.
On October 11, 1945, Chief Charles French died at his home. A career of 42 years with the Manchester Fire Department of which he served as Chief since 1917. His death was sudden as he was in his office at headquarters only two days before. Chief French was always receptive to trying new methods of firefighting or new equipment, and if practical, incorporate them into the department. One of the features he was the proudest of was the fire alarm system he had once supervised.
On October 15, 1945, Captain Aubrey Robinson, with 23 years of experience, was appointed as Chief of the Department to fill the office of the late Chief French. The new Chief had served as the late chief's driver the past 17 years.
A 3-alarm fire destroyed the four story Fournier Block at 1195-1225 Elm Street on February 15, 1946. The 8 hour battle drove 100 people from their apartments and burned the Fournier’s Hillsborough Furniture mart, the Red Arrow Restaurant, the Manchester Delicatessen, and Lemay's Jewelry store along with the Pearl Street Fruit store, a barber shop, and Lessard's Second Hand Furniture store. At 7:14 P.M. the first alarm was sounded as box #8 was pulled. As firefighters arrived a hot air explosion blew out every window in the block housing Fournier's Furniture. The 2nd and 3rd alarms were sounded at 7:16 P.M. and 7:22 P.M. respectively. The first floor of the Fournier’s Furniture and Manchester Delicatessen were fully involved as well as the upper three floors that stored extra furniture. Thousands of feet of hose lay encased in ice as well as ground ladders frozen to the fire building. A dozen high-pressure lines, ground nozzles, deck guns and aerials had done little to stop the inferno. An 18-room inn located south of Fournier’s was also heavily damaged.