Why don't they just close the whole thing down and get it over with?

It's not just the eastbound Ted Williams Tunnel that was ordered shut today. Mac Daniels reports:

... Two lanes of I-93 North from the O’Neill Tunnel entrance to the Atlantic Avenue on-ramp will closed at night until further notice from 11:30 p.m. to 5 a.m. the next morning. The two tunnel lanes will close alternately. Tonight the right lanes in the tunnel will be closed; tomorrow the left lanes will be closed. ...