A day of national mourning will be observed on Wednesday, Erdoğan said. ABC News' Somayeh Malekian contributed to this report.

This is a developing story. Please check back for updates. ABC News' Somayeh Malekian contributed to this report.

ABC News' Samy Zyara, Diaa Ostaz, Nasser Atta, Meredith Deliso, Somayeh Malekian and Joe Simonetti contributed to this report.

ISTANBUL -- A fire raged through a 12-story hotel at a popular ski resort in northwestern Turkey early Tuesday during a school holiday, killing at least 76 people - at least two of them when they ...