Teresa was traveling in a group from Mexico to the US. On 30 AUG 2010, Teresa informed her sister that she would begin walking the next day. While walking, Teresa started feeling sick and was lagging behind the group before the last Border Patrol checkpoint. She was left to sit under a tree by a dirt road so that she could be spotted by someone who could help her. Later, somebody reported seeing a woman on the side of the road but when Border Patrol went to look, they could not find anyone. Teresa has not been seen or heard from since 30 AUG 2010.