Locals are getting to weigh in on the L train shutdown. View Full Caption Imgur

UNION SQUARE — MTA Chairman Thomas Prendergast briefly lost his cool during nearly two hours of fielding questions from audience members, when someone called the idea of a full L train shutdown "outrageous" and wondered how the agency could even consider it.

Why wasn't the MTA more seriously considering a partial shutdown, wondered audience member Ralph Gleason. Closing the L train would be "outrageous even for a short period of time," he said, to which audience members erupted in applause.

"Sometimes you're dealt with a hand you have to deal with," Prendergast retorted, adding that he would have preferred that Hurricane Sandy hadn't flooded the Canarsie Tunnel or that engineers 100 years ago had figured out a better construction method so that they wouldn't have to close the tunnel in order to fix it.

"We don't have that option," said Prendergast. "As much as we know it's outrageous because of impacts, it must be done."

The MTA is still weighing two options — a full or partial shutdown of the tunnel, Prendergast insisted.

"People say, 'You're leaning towards one,' " Prendergast said. "No. We're having a dialogue."

The brief moment of emotion came sandwiched among dozens of audience questions about the details of construction plans and alternate service options at the second public hearing held by the MTA Thursday night in Manhattan to discuss the upcoming construction work on the Canarsie Tunnel that connects Manhattan and Brooklyn on the L train line.

Service between Manhattan and Brooklyn would be disrupted for 18 months or three years.

Construction is slated to begin in 2019.

Following the second of two public hearings on the construction work, MTA officials will now visit community boards along the L train line to glean more granular community input. In the next two to three months, they'll decide on whether to opt for a full or partial shutdown.

And while some Thursday thought a full shutdown should be off the table, Canarsie commuter Jillian Rodney said anything other than a partial shutdown would be, "unfair to people at the end of the line."

"[A partial shutdown] would mostly benefit Williamsburg riders," Rodney said. "Honestly, everyone else will still have to make the transfer."

WHAT DO YOU THINK? TAKE OUR SURVEY:

Full Shutdown: All L train stops west of Bedford Avenue including all Manhattan stops along the L train line would be closed down for around 18 months. Buses, J, M, Z and G train lines, and ferries could provide alternate service during that time.

Partial Shutdown: Service between Canarsie and Eighth Avenue would operate in two sections. Trains would run from Canarsie until Lorimer Street every eight minutes. Then shuttle buses would take riders from Lorimer to Bedford Avenue where a shuttle train service would cart passengers from Bedford Avenue to Manhattan. Those trains would run every 12 to 15 minutes, allowing one-fifth of the current capacity. This option would take around three years for construction to be complete.