The frigid morning came to a halting start for thousands of Boston commuters after an electrical problem forced a two-hour shutdown on sections of the city’s subway system.

"It's cold,” one commuter said. “It's extremely cold but at least I have layers on."

The cold weather also provided ammunition as Massachusetts Gov. Deval Patrick proposed a billion dollar a year investment in transportation.

“Just ask those people who were standing in the cold at Arlington Street this morning whether they want these investments,” Patrick said. “They get it.”

The shutdown forced up to 1,500 passengers to walk down tunnels to exits and onto 70 buses that were diverted to help.

The scene was confusing.

As the sun pierced through blue skies, the high barely touched 17 degrees with the wind chill well below zero. Boston officials scrambled to make sure the city's most vulnerable were out of harm's way.

“Our concern at this time: people with addictions can be particularly vulnerable, people who generally are fearful of overcrowded conditions in shelters who may be resistant to coming in,” said Boston Emergency Shelter Commission Director Jim Greene. “So we’re all on full operations to try to make sure that as many people are indoors and warm and safe as possible.”

In the middle of a three-day stretch of frigid temperatures, Boston will see the mercury drop into the single digits, until the weekend, when temperatures climb back into the mid-20s.