BOSTON -- Not true. That's the response from Big Dig officials, reacting to a published report that suggests fire doors in Big Dig tunnels are boarded up, blocked or missing as a result of work that's being done to repair leaks.

Friday, Boston's fire commissioner weighed in on the issue.

NewsCenter 5's Janet Wu reported that the question of whether motorists would be safe if there were a fire in one of the Big Dig tunnels came up as a result of a Boston Globe report. Big Dig officials said they would be.

"I think that this is outrageous that the public got up again this morning and read this story and, you know, once again thought that there was something for them to be nervous about in traveling through this tunnel system," said Big Dig spokeswoman Mariellen Burns.

Burns said of the 70 planned exits from the Central Artery tunnel, 57 are now open, more than required by federal law. She said the only exits that are still closed are those still part of the ongoing construction and fire officials have approved the current plan.

"We have never closed any doors that were agreed on this [fire] plan. We have never modified this plan," said Keith Sibley of Bechtel/Parsons Brinckerhoff, the contractor for the Big Dig.

Boston's fire commissioner agreed that the safety of the motoring public has in no way been jeopardized.

"Given the situations that developed in the tunnel -- that they do have some construction problems -- they're going in to fix these leaks. They are having to go into some of these areas to access behind the walls. Some of these stairwells are now inoperable. Should the tunnel be closed down because of that? I don't think so," Boston Fire Commissioner Paul Christian said.

Artery officials said no exits have been shut down to repair leaks or slurry walls.

"We've tested the safety and we've drilled for safety. When we opened northbound, we literally represented a large megawatt fire by lighting a pool of diesel on fire at the lowest point of the tunnel to see how it behaved," Sibley said.

The fire commissioner pointed out that a fire in the Ted Williams Tunnel last year was not detected by heat sensors until it was almost extinguished. It caused a traffic jam, but no one was hurt.

"We're watching this very closely. I have other concerns in the tunnel, and it's going to be long-term maintenance issues. I certainly want fire retardant reapplied to those beams above the ceiling," Christian said.

Big Dig officials said it will take a couple more months to finish that project. Meanwhile, this week they discovered 19 more panels that were defective. That means a total of 53 panels that need to be repaired, but that is out of 1,200 panels that have been inspected -- and a quarter of all the panels that still need to be examined.