MONROE, N.C. -- A lawsuit filed in Monroe on Friday asks a judge to stop Union County's animal shelter from killing young, geriatric, injured, sick or pregnant animals in its gas chamber. �We hope to stop the inhumane euthanasia of defenseless animals,� said Sue Ratliff, head of the Humane Society of Union County. Her group and another, the North Carolina Coalition for Humane Euthanasia, are suing Union County. They support lethal injections for euthanasia. Their attorney, Rodney Alexander, said many of the deaths in Union County's gas chamber violate state law. �Union County's sheriff's department, based on documents we've received from them, is euthanizing young, sick, injured, old and pregnant animals in the gas chamber,� Alexander said. �We believe that it's against the law.