A couple honeymooning in Colorado died in a plane crash on Monday, authorities said.

Costas John Sivyllis, 30, and his 33-year-old wife, Lindsey Vogelaar, were married just four days when they died shortly after taking off from the town of Telluride on their way back to home to Florida, according to the San Miguel Sheriff’s Office.

The two had flown out to Colorado in their Beechcraft Bonanza for a small wedding and honeymoon, the sheriff’s office said.

Sivyllis and Vogelaar both worked for United Airlines, he as a pilot and she as a flight attendant, the bride’s family told Wood-TV.

“Lindsey was the most fun, energetic person ever with an infectious laugh and smile,” Vogelaar’s family said in a statement to the network.

“Costas was genuine and made people feel like they mattered. He was calculated and Lindsey was the wings he needed to seek adventure.”

The National Transportation Safety Board is investigating the crash, which authorities believe happened about 15 minutes after the plane took off.