Transcript for Water heater gas leak likely killed family: Official

Back now with the latest on the spring break tragedy in Mexico where a family of four from Iowa was killed by a deadly gas leak in their condo. Gio Benitez is here with the details. Authorities now think they know where it started. Reporter: It appears to be from something so many of us have in our own home, a water heater happening at a rented condo during their vacation but it's not just for vacationers, it's for all of us. This morning, officials in Mexico now reportedly revealing that a gas leak from a water heater is what likely killed the sharp family in a Mexico condo. Relatives saying the gas seemed to have killed the two adults and two children without warning. Kids were on the floor watching TV and Kevin and Amy were laying on the bed watching TV. The TV was still going apparently. Reporter: 41-year-old Kevin sharp and his wife Amy had surprised their children, 12-year-old sterling and 7-year-old Adrianna with a trip to tulum. The prosecutor telling local media the water heater was leaking gas maybe from use or lack of maintenance and that a high level of gas was found. One deadly gas that can be emitted from a faulty hot water heater is carbon monoxide. If you don't mind I'll do a quick inspection. Reporter: Steve driver, a technician with the pse & G company says if it's not ventilated properly say due to a blocked chimney that silent killer can seem back into your home. Your flue gas is going up and out and potentially it will go back into the living space and if you don't have your detectors you have a problem. He has a simple match test above the hot water heater. A flame pulling towards the flue is a sign that it's clear of any blockage. When you blow out the match the smoke should also go up into the flue. You put it near that and instantly blew that out there is a potential for a blockage in that chimney. Reporter: A possible killer of the family that loved to travel the world. She posted hundreds of pictures of all their trips and we'll always have them. Reporter: Of course, don't light that match if you smell any gas at all. Experts tell us there are a few things can you look for in your home to know whether carbon monoxide is building up like looking for significant condensation on walls and windows. Another sign, your house pets can become sluggish so if you suspect any co at all get out and call that fire department. There are detectors that you can bring with you. There are detectors and not expensive. You shared that with us yesterday, Amy. You can bring them and plug them in which is incredible. I didn't know those existed. We should do that. Thank you.

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