A very close call on Tuesday evening for a pair of teens in Cambridge.

Waterloo Regional Police say the teens went exploring last night in an underground tunnel in Galt that connects Mill Creek to the Grand River.

Police say the pair found themselves in trouble when they encountered rough water.  

Fortunately, one of them had a cell phone and called for help, but it took police and fire some time to figure out exactly where they were and then to bring them up to safety.  

Police say the two were not hurt, but a male teen is facing a charge of trespass to property.