That's a heartbreaking and deeply tragic event. Here's a rephrased version of the news story in a more formal and concise tone:

Gunman Opens Fire at Minneapolis School, Killing Two Children

A shooting at Annunciation Catholic School in Minneapolis, Minnesota, left two children, aged 8 and 10, dead and at least 17 others injured on Wednesday morning. Among the wounded are 14 children, with seven currently in critical condition, according to hospital officials.

Police say the gunman opened fire through a church window before fatally shooting himself. The motive behind the attack remains under investigation.