Police say a woman placed a 2-week-old girl on railroad tracks in Pueblo and ran away, but two city workers immediately rescued the infant, who appeared to be unharmed.
Police said the baby was taken to a hospital as a precaution after the incident Friday.
Witnesses told police two trains were on the track but neither was moving. It wasn't clear how close the trains were.
Witnesses chased and held the woman until officers arrived.
A police news release says the woman was incoherent and was taken into custody for questioning and evaluation. The statement didn't say if she was arrested on criminal charges. A police spokesman didn't immediately return a call.
The statement says the woman was wanted on a warrant for failure to appear on a theft charge.