(CNN) -- Logan Stevenson's role as best man at his parents' wedding Saturday came just in time.
Logan, a 2-year-old terminally ill Pennsylvania boy whose parents moved up their ceremony so he could witness it, died Monday night at his home in Jeanette with family at his side, Westmoreland County Deputy Coroner John Ackerman said Tuesday.
The child died of complications from the genetic disorder Fanconi anemia, Ackerman said.
His parents, Christine Swidorsky and Sean Stevenson, had planned to marry in July 2014, but they moved it to Saturday after being told that Logan -- suffering from leukemia brought on by the genetic disorder -- would not live much longer.
On Monday, Logan's parents held him for long periods after it became apparent that his death was near, his mother wrote on Facebook.
"At 8:18 my son took his last breath in my arms," the mother, now known as Christine Swidorsky-Stevenson, wrote Monday night. "Im so sad upset and im in disbelief he is with angels and he's in no more pain. no more sickness no more hospitals."
On Saturday, Logan, dressed in a tan suit and an orange shirt matching his mom's bouquet, looked on as his parents exchanged vows at a backyard wedding in Jeannette.
His mother carried Logan down the aisle, and his grandmother cradled him in her arms, his favorite brown teddy bear by his side.
"We waited for this day for a long time ... but under the circumstances with Logan being sick all the time, we just held off. We just knew he was gonna get better," the groom told CNN Pittsburgh affiliate KDKA. "But under the circumstances of what the doctors told us, we just decided to go ahead and do it while he is still with us."
The wedding came eight days after the couple was told Logan had one to two weeks to live.