Chattanooga, TN- Three Chattanooga residents were sent to the hospital Wednesday morning after apparently succumbing to carbon monoxide poisoning.

The Chattanooga Fire Department received the alarm at 9:31 a.m. and responded to 1205 East 35th St.

Captain Ken Atkins with Engine 14 said all three residents were outside the mobile home when firefighters arrived on the scene.

Details are a little sketchy, but relatives of the victims reportedly stopped by the residence this morning to take one of them to work. When no one answered the door, the relatives entered the home and found one victim unconscious and two others appearing to be very sick.

The relatives pulled the three victims out of the home and called 911. Paramedics with Hamilton County EMS then transported the victims to Erlanger Medical Center.

At the time of this release, two victims were listed in critical condition, and the other victim was still being evaluated in the emergency room.

Captain Atkins said technicians with the Chattanooga Gas Company confirmed that there were elevated levels of carbon monoxide in the residence, and that it was most likely caused by a defective gas wall heater. If those relatives had not stopped by when they did, Captain Atkins said the victims would not have survived.

Captain Atkins added that while he did find a smoke detector in the home, he did not find a carbon monoxide detector, which he said is crucial to have if you have a gas heater or wood-burning stove.