HARTFORD, Conn. (AP) - The Connecticut Department of Children and Families is investigating after authorities say a 4-year-old girl left school and started walking home alone after she was sent to the office to be picked up early.

Police say the girl was going to be picked up early Tuesday from the Thirman Milner School in Hartford but was sent to the office prematurely.

When she didn't see her mother, police say the girl walked about a half-mile to her home and was spotted by a woman who then followed her to make sure she got home safely.

No criminal action has been taken. The school is conducting an internal investigation.

Hartford Public Schools interim Superintendent Dr. Leslie Torres-Rodriguez tells WVIT-TV that they have started to revise procedures for all schools.