BURLINGTON, Vt. (AP) – Two people remained hospitalized in critical condition Monday from carbon monoxide poisoning at an apartment complex near the University of Vermont.

Kerry Anne McCarthy, 20, of Montpelier, a UVM student, was being treated at a Boston hospital; Ginger Aldrich, 22, of Waterford was being treated in Montreal.

Jeffrey Rodliff, 23, of St. Johnsbury, Vt., was found dead and six others were hospitalized after emergency crews were called to the privately owned Redstone Apartments around noon on Sunday. Two police officers and a maintenance employee also were treated and released.

Four of the six injured were UVM students.

The 11-building Redstone complex remained closed Monday as the investigation continued to find more specific source of the leak.

Roughly 200 tenants, primarily UVM students, were being housed at local hotels.

A preliminary investigation found that the building’s gas-fired hot water boiler malfunctioned, said John Wood, director of fire safety for the state fire marshal’s office. There were no carbon monoxide detectors in the building, he said.

UVM will install carbon monoxide detectors in campus buildings in coming days, said UVM spokesman Enrique Corredera said.

“We met with the property owner today and communicated with clear expectations that our students should not return to building until every building has been inspected,” and carbon monoxide detectors have been installed, Corredera said.

The apartments are owned and operated by Novarr-Mackesey of Ithaca, N.Y., on land leased from the university.