The rest of the dome will be entirely covered by January 2013. The entire project should take three years to complete. (Brandon Rittiman/9NEWS)
The measure died late Tuesday night after Republican leaders halted floor work when Democrats, in the minority, tried to force a debate and vote on the bill.
Hickenlooper, during a 15-minute press conference on Wednesday afternoon, came to tears, saying civil unions are a "civil rights issue" that should be legal in Colorado.
"We've had over 500 calls and emails this morning, and an overwhelming majority thinks we need to have a special session," Hickenlooper said. "We need to have an open discussion of the issue and again at least work on a resolution."
The bill was one of several that needed initial approval before Tuesday at midnight to survive.
A total of 37 bills in all, including the civil unions bill, were left in limbo by the State House.
The list of bills includes an overhaul of school discipline policies and setting a standard for what's considered too high on marijuana to drive.
That bill is an effort to set a 5 nanogram limit for THC in the blood as a result of smoking marijuana. The bill had passed the Senate this year and was expected to receive enough support in the house to pass. District attorneys had lobbied hard for this bill, seeking a standard for marijuana impairment - a standard that would be readily explainable to jurors used to standards for alcohol in the blood.
The school discipline bill would give schools more discretion when doling out expulsions and suspensions.
There is also a bill that criminalizes the manufacturing of so-called bath salts and one that provides $20 million to certain water projects.
Hickenlooper says he hoped bills about public safety and jobs would be passed.
Republican House Speaker Frank McNulty says he would not support a civil unions measure, but promised to do the work of the legislature during a special session.
"He would like to see that bill on his desk. I certainly have a difference of opinion with him on that," McNulty said. "I'm not a supporter of gay marriage and the governor's perspective is that - his perspective."
The last Colorado special session happened in 2006 to debate immigration bills.
The cost of the special session is $23,500 per day, according to the Legislative Council.
However, Hickenlooper says the state has budgeted roughly $350,000 for a special session so there is no extra cost to taxpayers.
He also says the work would begin soon, either Friday or Monday.
PDF Document: FAQ about special session
(KUSA-TV © 2012 Multimedia Holdings Corporation with The Associated Press)