An American Airlines flight from London to Philadelphia landed in Ireland after cleaning chemicals leaked in the aircraft cabin on Monday.

“American Airlines flight 729 from London Heathrow to Philadelphia diverted to Dublin due to an odor caused by a spilled cleaning solution in the galley,” an American Airlines spokesperson said in a statement.

Katie Phillips, a passenger on board the diverted flight, tweeted that a “chemical spillage” led to a “sickness outbreak” on the plane.

Phillips told CNN the odor smelled, “slightly sweeter than fuel.”

“We were delayed for nearly an hour at Heathrow when they suspected a strange smell,” said Phillips, adding that the aircraft took off anyway.

People on the plane started to feel unwell after takeoff, and that she saw one flight crew member seemingly taken ill, Phillips said.

“I could see her,” said Phillips, who did not feel sick or show any symptoms herself. “She was surrounded by other staff members,” she added.

American Airlines told CNN: “We’re fully investigating the specifics on what happened on this flight.”

The plane landed in Dublin at 1:15 p.m. local time, said the airline.

“Medical personnel have met the aircraft to evaluate any crew members or passengers who may need additional assistance,” the airline spokesperson said.

Two crew members and one customers were taken to the hospital for evaluation, the airline confirmed.

A spokesperson for Dublin Airport told CNN that the flight was diverted there for a medical emergency.

“As per standard operating procedures there was a full turn out of Dublin Airport’s emergency fire services,” the spokesperson said.