This is a relic of the cold war. Most of AT&T's telecom buildings were designed to be able to withstand just about everything except a direct nuclear strike.

While services were impacted, none of the actual infrastructure was really damaged and they likely just need to repair the lines running up to the building.

TLDR: AT&T's telecom infra is a relic of the cold war and is designed to withstand almost any type of attack.