DENVER (KDVR) — A Delta Air Lines flight made an emergency landing in Denver on Monday night.

Delta 339 was traveling from Hartsfield-Jackson Atlanta International Airport to Seattle-Tacoma International Airport when it lost pressurization.

Allison Kropff was onboard the flight on her honeymoon. She said the plane lost altitude, the lights went off inside and the oxygen masks dropped from the ceiling.

The Boeing 757-200 airplane shows a sudden drop in altitude at 1 hour and 51 minutes into the flight, according to FlightAware. The plane dropped from a cruising altitude of 28,000 feet to about 10,000 feet in just under 7 minutes, the flight data shows.

The plane landed safely just after 7 p.m. and taxied to the gate, according to a spokesperson with Denver International Airport.

A Denver Health spokesperson said two to three passengers were being treated after the incident for symptoms like light-headedness and shortness of breath.

Delta had not yet responded to a request for comment on Monday night.