The crash in Canada's capital city between a double-decker bus and a Via Rail train occurred about 8:48am local time (1.48pm BST)
CBC News reports all of Ottawa's emergency responders are heading toward the scene.
All the dead and injured were on the bus, authorities said.
More top news
Anticipation is building ahead of this year's Bafta awards ceremony which is being held at London's Royal Opera House.
A man has been charged with the murder of 36-year-old Leanne Wall in Whitefield.
Five Britons have died after the car they were in plunged more than 80 feet from a bridge into a Swedish canal.