A trio of new passenger boats should be mothballed until a recent fire aboard one of the vessels is investigated, the city’s ferry union said.

The Marine Engineers’ Beneficial Association — which represents captains, mates, and engineers on the Staten Island Ferry — wrote a letter to the city Department of Transportation,calling for three Ollis-class ferries to be put out of service while the city probes the blaze on the Sandy Ground ferryboat last week.

The class of ferries are named after US Army Staff Sgt. Michael Ollis, a New Dorp native who was killed in Afghanistan in 2013. All three began running this year and include the MV SSG Michael H. Ollis, the Dorothy Day, and the Sandy Ground Ferry, which caught fire last week and forced hundreds of passengers to evacuate.

The three 4,500-passenger ferries were built by Eastern Shipbuilding Group and were funded through the city, state and federal government for about $314 million. 

The first of the trio to enter into service was the SSG Michael H. Ollis in February followed by the Sandy Ground in June. The Dorothy Day arrived in New York City in September and was commissioned in November, but it has not yet been put into service. 

Now, the union says there are too many safety concerns to allow passengers onboard.

“We are calling for an immediate docking of all Ollis-class vessels.” union treasure Roland Rexha wrote in a letter to NYCDOT.

“Based on the U.S. Coast Guard’s preliminary reports of a fuel leak causing the fire, there are far too many unanswered questions to put those onboard all Ollis-class vessels at any further risk,” Rexha continued. “These vessels are brand new to our harbor and we must insure they are able to provide safe passage to all New Yorkers.”

The union’s call to suspend service on the new ferries comes just one day after a group of New York City Council members called for an investigation into the boats, SILive reported.