After spending the morning taking in the breathtaking sights at Niagara Falls, a group of tourists boarded a bus to return to New York City, not knowing about an hour later, their bus would be lying on its side in the ditch off the New York State Thruway.

A tour bus with more than 50 passengers lost control and rolled over on the New York State Thruway near Pembroke, killing five people, police said.

A rescue operation is underway after a collision involving a tour bus and a semi-truck in Upstate New York on Friday, officials said. The "serious crash" occurred on Interstate 90 in Pembroke, near Buffalo, according to New York State Police. Images from the scene showed the bus on its side and a large emergency response.