Volunteer firemen came from Brooklyn and even Philadelphia to assist in fighting the fire. Explosions took down more buildings as warehouse supplies caught on fire. Meanwhile, marines and sailors from the Brooklyn Navy Yard were brought in for crowd control. Under the command of Captain Walker, they formed a chain of sentinels along South Street, from the Fulton Ferry to Wall Street, up Wall to Exchange. They provided some protection for the goods flung from the burning biuldings. Still many looters made out well during the fire. Somer merchants gave away blankets, hats, and other items to poor citizens who asisted with the rescue of merchandise.
By 12:30 A.M., the fire had progressed towards Wall Street and threatened the Merchant Exchange. The buildng, made of marble, was considered fire proof. Three stories high and spanning 115 feet, it was one of the largest buildings in the city and was located on the south side of Wall Street. Inside the main exchange room was a rotunda 75 feet long, 55 feet wide, and 45 feet high. The building had been completed and first occupied in July, 1827. As the fire progressed, merchants, not taking any chances, rushed down to retrieve their merchandise. The building, however, was not immune to the fire's destruction. At 12:30 A.M., the building began to smolder; by 2:00 A.M., it was engulfed in flames. Having little chance to suppress the fire, Gulick ordered his firemen to help the merchants remove their goods from neighboring structures, though it was unclear where the fire would strike next. The financial and commercial district was compeltely overcome. Even ships along the piers took flame.