A second teenager from outside Nebraska has been left at an Omaha hospital under the state's unique safe-haven law, apparently after his parent flew to the city specifically to abandon him, state officials said Monday.

A 13-year-old Michigan boy was left at Creighton University Medical Center between 1:30 a.m. and 2 a.m. Monday, said Nebraska Health and Human Services spokeswoman Kathie Osterman.

Since July 18, when the new law went into effect, 18 children between the ages of 1 and 17 have been abandoned. Nebraska's safe-haven law allows children as old as 18 to be left at state-licensed hospitals without fear of prosecution.

This is the second time that a child from outside the state has been left at a hospital in Nebraska. It's not clear why the boy was left, Osterman said. He was placed in an emergency shelter.

Last week, a 14-year-old girl from Iowa was left at an Omaha hospital by her grandparents. She has since been returned to her family.

Her abandonment set off concerns that Nebraska's broadly written law could make the state a dumping ground for unwanted children. Officials with the state's Department of Health and Human Services have stressed that the safe-haven law should be used for children in immediate danger only.

State offices were closed for Columbus Day Monday, slowing the investigation.

Officials have said parents and caregivers contemplating using the law should understand there is no guarantee a child could be returned to them if they change their minds. The placement may involve the courts, and the process of regaining custody may prove difficult.

Several of the parents or guardians who have left children cited uncontrollable behavioral problems as reasons for using the law. An out-of-work widower who left nine of his 10 children — ages 1 to 17 — said he simply felt overwhelmed by his responsibilities. That man, Gary Staton, has asked a judge to approve state-supervised visitation with the children he abandoned.

Officials have encouraged parents to seek other resources before resorting to abandonment. They've urged desperate parents to ask for help from family, faith-based groups and other community services before abandoning their children at hospitals.

State lawmakers and Gov. Dave Heineman have said the safe haven law, which was intended to protect infants, needs to be changed. The current law uses the word "child," which some have taken to mean "minor," or anyone under the age of 19.

The Legislature's Judiciary and Health and Human Services committees plan to hold a joint public hearing on the safe-haven law on Nov. 13.