Special Report: What Would You Do?

How structurally safe is this structure? "It’s overdesigned to address any anticipated earthquakes in the Boston region," Mike Lewis, Tunnel Project Director, said

Lifted high above the road where crews are fixing all of those leaks. The project director shows us the difference between what happened back in September and the leaks we are hearing about today.

"If you had a leak like this in your basement and you had a sump pump you probably wouldn ’t worry about it," Lewis said.

Officials insist a flood can’t happen. But do they have a plan for the worst case scenario such as the tunnel flooding some day?

"Water at that point was coming into the tunnel at what we estimate to be 250 gallons a minute which is a significant flow. Every one of our pump stations has a capacity to pump at a rate of 1,200 gallons a minute, which is, more than four times that amount and we have 12 of these pump stations," Bill Connell, Chief Mechanical Engineer, said.

If the emergency were a fire, giant fans would release fresh air and suck out the smoke. It is a plan that has been put to the test.

A practice drill was set inside the I-93 tunnel back in 2002. Boston firefighters put the emergency ventilation system through a test run.

Instructions would broadcast over your car radio and on message screens. If you see smoke or have to get out of your car for some other emergency head to an exit.

"Every 300 feet we have the ability to get to an areas of safety," Connell said. Some will lead you to the safety of the streets.

Another way out of the tunnel on foot is the cross packages. If you climb up on the roadway you’ll see these strobe lights indicating where they are. An emergency door will slide open and you’ll step from one tunnel to another to safety.

An interesting fact is the I-93 tunnel where the breach occurred is under ground, not under the ocean. You can tell by the color of the tiles on the tunnel walls.

If you see a strip of blue tiles you are under water. If the strip is a brownish orange color you’re under land.

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