That reminds me of this story I posted 4 years ago...
Family of 3 found dead (Car left running in Garage)
San Antonio Express-News ^ | 04/24/2009 | By Jeorge Zarazua and Alejandro Martinez-Cabrera
Posted on Friday, April 24, 2009 8:45:52 AM by Responsibility2nd
http://www.freerepublic.com/focus/f-news/2236828/posts
My friend and his brothers (in school at the time) escaped the same fate only because the neighbors came by, peeked in a garage window, saw the bodies inside the garage, broke in to remove the poisonous gas and called the police.
Much too late however...