Two men who parachuted from PPG Place may have gained access to the building with a copy of the key.
Building officials believe a contractor may have made a duplicate key in March, according to TribLive news partner WTAE.
The locks have since been changed and the duplicate keys have been disabled.
The pair of jumpers could face trespassing charges and additional counts if police identify them.
Security cameras recorded the men entering One PPG Place near Stanwix Street and Third Avenue about 4:45 a.m. April 9 wearing dark hooded jackets. They made their way to the roof and jumped off.
The men appeared to be BASE jumping enthusiasts. It’s a thrill-seeking hobby akin to skydiving, but, instead of jumping from an aircraft, people jump from a building, antenna, span or earth — hence, “BASE” jumping.
Police are still working to identify them.
The main tower of PPG Place is 635 feet tall.
PPG Place Senior General Manager Chris Urban told WTAE no one was hurt and nothing damaged.
A letter to customers said steps are being taken to ensure a breach doesn’t happen again.
BASE jumping requires a slightly different parachute that opens faster because most jumps happen under 2,500 feet, the lowest altitude that skydivers will jump from, experts told TribLive.
It isn’t uncommon — though it remains illegal — to BASE jump in Pittsburgh and most other places.