Roger Kaiser, identified as the audience member who walked to the front of the stage during an intermission to sprinkle his friend's ashes in the orchestra pit, wrote a letter of apology addressed to "Mr. Gelb and the entire Metropolitan Opera community."
"A sweet gesture to a dying friend that went completely and utterly wrong in ways that I could never have imagined," Kaiser wrote in the letter.
The rest of the performance of Rossini's "Guillaume Tell" was canceled as a safety precaution, and the opera house was ordered evacuated when witnesses reported seeing Kaiser sprinkle a white, powdery substance into the pit.
The evening performance of Rossini's "L'Italiana in Algeri," conducted by James Levine, was canceled as well.
Kaiser lamented that he may not ever forgive himself for depriving his fellow patrons of the performance, the first time the opera was performed at the Met in 80 years, attributing his actions to "an enthusiasm that blinded [him] from seeing the potential risks."
Kaiser did not respond to CNN's request for comment.
The incident, forcing the Met to close until Monday, cost the Met thousands of dollars in cancellations and refunds. The Met advised the New York Police Department, however, not to press charges against Kaiser.
This is the first time in Met history that the opera house was closed and performances were canceled due to a terror scare. Other than weather-related incidents, two midperformance deaths in 1988 and 1996 were the only incidents to cause cancellations during a show, according to Met Press Director Sam Neuman.
Saturday night after the scare appeared to be nonthreatening, Met General Manager Peter Gelb, appeared immediately relieved.
"Ashes of an opera-loving mentor being sprinkled into the pit, although inconveniencing all of us, is a far cry better than anything else," he said.
Kaiser went on in the letter to share details of his late mentor. He said Terry Turner was an opera aficionado he first met as a regular at the restaurant at which Kaiser worked. The two wrote letters and met on occasion to see operas together.
Turner died of cancer in 2012, and Kaiser wrote he promised he'd take Turner's ashes to opera houses. "He would be there forever enjoying all the beautiful music," Kaiser wrote of his promise.
Kaiser will be allowed to enjoy future performances at the venue, according to Gelb's response.
"I trust that your future visits to the Met will be without incident, and that you will continue to proselytize about your love of opera to all those who will listen," Gelb said to Kaiser in an email.
Gelb accepted Kaiser's apology via email and wrote that he appreciated its sincerity.
"We appreciate opera lovers coming to the Met; we hope that they will not bring their ashes with them," Gelb said on Saturday.
Correction: An earlier version of this story misstated the manner in which Roger Kaiser approached the Orchestra pit. He walked to the front of the stage during an intermission to sprinkle his friend's ashes.