No, the the Sears Tower bombing is attributed to Alamos 20,000 proper. The Hand(s) of Five is only mentioned in relation to the events in Seattle.
QUOTE
The Neo-Anarchist's Guide to North America, page 105
In 2029, the waves of anti-metahuman violence set off by Seattle's Night of Rage swept through the country. It was widely believed that the most radical arm of Alamos 20,000, the Hand of Five, was responsible for the warehouse fires that caused the tragic deaths of hundreds of Seattle's metahuman population on that night. The terrorism continued all over the world in the days that followed.
Three days after the Night of Rage, members of Alamos 20,000 committed the most outrageous act of terrorism yet, the second major event affecting Chicago. IBM had acquired the Sears Tower years earlier. From the beginning of the Awakening, the computer company supported an equal-opportunity program, just when it seemed as if people could begin to pick up their lives and go on in the wake of the Night of Rage, the terrorists of Alamos 20K, with a combination of magic and explosives, destroyed the balance of the nine units making up the Sears Tower, sending the building down to the street during a weekday lunch hour.
The falling debris destroyed blocks worth of buildings, streets, and sidewalks. Thousands were crushed to death, but it was still not over. When gas lines were ruptured, the whole Loop area went up in flames. A second Chicago Fire was narrowly averted by mages who managed to contain the blaze in less than an hour. The damage was still severe, with the death toll reaching nearly 26,000.
The physical damage was not the worst part of the incident. Alamos 20K made the destruction of the Tower look like metahuman retaliation for the Night of Rage.
The Neo-Anarchist's Guide to North America, page 108
When Alamos 20K destroyed the Sears Tower, the nine smaller towers making up the building fell away from each other, crushing other buildings and the people in them for four blocks.
Bug City, page 43
When Alamos 20K destroyed the Sears Tower, the nine smaller towers making up the building fell away from each other, crushing other buildings and the people in them for four blocks.
Feral Cities, page 6
Disguised as an act of metahuman retaliation, the terrorist organization Alamos 20,000 blew up the Sears Tower, killing thousands and damaging the surrounding buildings.