BOSTON -- The Interestate-90 connector tunnel remained closed Wednesday as officials located dozens of areas in the eastbound connector tunnel where questionable tieback systems may have been used.

NewsCenter 5's Jack Harper reported that problems with the bolts that hold the ceiling tiles in place were uncovered in 1999. A 12-ton section of the ceiling fell Monday night, killing Milena Del Valle, 38, whose car was crushed by the panels.

"We have approximately 60 locations on the eastbound side -- what we are going to identify as isolated locations," Massachusetts Turnpike Chairman Matt Amorello said.

The tieback system that failed in the fatal collapse was more widely used in the I-90 tunnels than previously thought.

"There are individual locations, done based on a visual inspection of all the locations in the I-90 tunnel, both east and west and HOV, where there were bolts. These individual locations where the threaded bolts were used, where something appears to have pulled out or be somewhat of a gap between the ceiling, those have been identified as potentially problematic. Those are being investigated further," Big Dig project director Mike Lewis said.

Big Dig workers have been slowed in their inspection and potential repairs.

"We will be taking them down in a fashion that they are satisfied with, which means taking down pieces, marking them as evidence, sealing those pieces and those that can be placed into evidence bags, and documenting them as appropriate for an investigation of this nature. It is taking us more time than we would have anticipated," Amorello said.

Attorney General Tom Reilly confirmed that anchor bolt concerns were raised in 1999.

"They were not only identified, but there was a plan to address that problem. What we are trying to determine right now is was that plan implemented?" Reilly said.

Reilly said that his office has put Big Dig contractors on notice that they will be subpoenaed to testify.

No suspect areas were identified in the Ted Williams Tunnel, officials said.

Meanwhile, Milena Del Valle's husband, Angel Del Valle, who was not seriously injured in the accident, remained in seclusion with family members Wednesday.

Angel Del Valle thanked the group of people who waited to talk to him outside his sister's Dorchester home. A large bruise was visible on his forehead.

Tony Barros, a special assistant to Boston Mayor Tome Menino, spent several hours with the family.

"He is coping with the situation as best he can. It is a very difficult time," Barros said. "We are here to offer condolences and support to the Del Valle family."