Capt. Simeon Ecuyer, the Swiss-born commander of Fort Pitt, may have thought he had overcome the worst of his problems in March 1763.

Death and destruction caused by natural forces, however, soon would be followed by man-made mayhem.

Three days of heavy rain began March 6.

On March 7, as the "river continued to swell," he had soldiers remove provisions and ammunition from the ground floor of all buildings within the fort. "[W]orked all day closing the drains, preparing everything against inundation as best I could," Ecuyer wrote his commander, British Col. Henry Bouquet, in a letter dated March 11. By 10 p.m. the rising Monongahela and the Allegheny rivers turned the land on which the fort stood into an island, he wrote.

By 4 a.m. the next morning, the interior of the outpost was covered with six inches of water.

The next afternoon he "detached two officers and thirty men to the upper town with fifteen days' provision for all the garrison." The "upper town" referred to the small commercial settlement built on higher ground along the Monongahela River. It began a few hundred yards upstream from the fort.

At midnight Ecuyer ordered all available boats and barges be brought into the fort. Since wagon access had been cut off by the rising rivers, his plan was to load artillery, arms and other supplies into watercraft and float them out. Fort Pitt would be abandoned until the floodwater receded.

"[B]ut happily on the 9th, at 8 o'clock in the morning, the water was at its greatest height and at midday it fell two inches," he wrote. "All the provisions and ammunition are saved and in good condition."

Physical damage was minor.

"The shop of the blacksmith entirely gone," he wrote. "[T]he little wood gathered for the construction of [new] boats has followed several house of the lower town [into the Ohio]. All the fences of the garden carried off by the ice."

While no lives were lost at Fort Pitt, the flooding claimed at least two victims nearby. "Thomson the tanner, and Shepherd the carpenter, are drowned, the first at Turtle Creek and the other at Two Mile Run," he wrote.

Less than two months later, Ecuyer had much more to worry about than lost fences. "Yesterday evening the Indians massacred the two men we had at the sawmill," he wrote to Bouquet on May 3. "They scalped them and left a head breaker or Tomahawk, which signifies I believe a declaration of war."

He was right. No sooner had the French and Indian War ended than Pontiac's Rebellion began. Native Americans had returned to the warpath as land-hungry farmers from Eastern Pennsylvania and Virginia continued to cross the Allegheny mountains to settle in what was known as the Ohio Country. Delaware, Shawnee and Seneca warriors concluded that the British government was not going to keep its promise that the area around Pittsburgh would be left to them.

Ecuyer's letters to Bouquet and a 1763 journal kept by Capt. William Trent, another officer at Fort Pitt, described the violence of the next few months. Both documents are included in "Fort Pitt and Letters from the Frontier," a book published in 1892 by J.R. Weldin & Co. Its editor was Mary Carson Darlington.

Once the Indians began their siege in late June, anyone venturing outside of the walls of Fort Pitt was in danger.

"About 5 o'clock one James Thompson, who it was supposed [had] gone after a horse, was killed and scalped in sight of the fort," Trent wrote in his journal on June 22.

Two days later, two chiefs, Turtle's Heart and Mamaltee, offered safe conduct to the garrison if soldiers and civilians agreed to leave immediately. Ecuyer replied "that we could defend it against all the Indians in the woods," Trent wrote.

Trent's journal also describes an early attempt at biological warfare against their Native American foes. "Out of our regard for them, we gave them two blankets and a handkerchief out of the Small Pox Hospital," he wrote. "I hope it will have the desired effect." There is no evidence that this early attempt at weaponizing disease germs was effective.

The Indians did not withdraw from around Fort Pitt until late August after a relief expedition, commanded by Bouquet, defeated them in the two-day Battle of Bushy Run.

The Pennsylvania frontier, however, remained a dangerous place.

On Oct. 19 a Highlander guarding cattle was shot and killed along the banks of the Mon. "[T]here were but two or three Indians," Trent wrote in his journal. "They scalped him."