Emergency officials warned major flooding was expected along the Mendenhall River late Tuesday through Wednesday, with flood waters expected to crest Wednesday before noon.

Meltwater is escaping from a basin that is dammed by a glacier - prompting fears of a deluge in state capital Juneau.

Officials in recent days have been warning people in the flood zone to be ready to evacuate. On Tuesday morning they confirmed water had started escaping the ice dam, with flooding expected late Tuesday and on Wednesday.