A few years later, the Fire Nation attacked Tyro's town. Tyro and his fellow earthbenders were outnumbered ten to one, but nonetheless fought back bravely. They were ultimately defeated, however, and subsequently detained in an offshore prison rig, constructed entirely from metal. He remained a leader and an inspiration to his people, even during their depressing imprisonment.
Tyro worked hard to keep the prisoners alive throughout their long captivity. Unwilling to engage in hopeless combat on a prison rig without earth to bend, he did not favor open resistance with his captors; even Katara's heartfelt persuasion to mutiny failed to goad him to battle the Fire Nation soldiers. However, when Aang provided a source of earth and his son Haru showed a willingness to fight, Tyro shed his reluctance and helped lead the fight for freedom. After their victory at the rig, Tyro stated his intentions to defeat the Fire Nation Army and take back his village, which was eventually fulfilled.
In the summer of 100 ASC, he, Haru, and other earthbenders were brought by Hakoda and his battalion of Southern Water Tribe warriors to the Black Cliffs. The small army invaded the Fire Nation during the solar eclipse. After Aang failed to defeat the Fire Lord, the submarines were destroyed and the invasion force became stranded. The younger ones, including Haru, were sent to escape with Aang on Appa while the older warriors, Tyro included, stayed behind and were taken captive.
Tyro was freed from imprisonment shortly after the Hundred Year War ended, and reunited with Haru.
Tyro was a skilled earthbender. He was able to create a wall of coal, easily blocking the warden's fire blast. In addition, he and four other earthbenders, including Haru, created a shield strong enough to withstand a combined blast from several firebenders. Together, he and Haru were able to compress a large amount of coal into a single projectile, a difficult feat to accomplish. He was also a capable teacher, having personally taught his son earthbending, eventually helping him become a proficient earthbender.