On April 10, the first chick hatched at 2:20 p.m. Brussels time, and the second chick hatched at 3:26 p.m. The other two chicks hatched during the night of April 10 -11. This meant that all four chicks hatched in well under 24 hours, which is quite unusual.
When I checked the site on April 11, I was greeted by four high-pitched little voices, one deeper voice and loud cathedral bells.
Mom was feeding the chicks and talking to them at the same time.
The male's bands were read a few days ago. He was born at the Cathedral between April 6 and April 8, 2008, one of a clutch of three males and one female. He fledged on May 18, 2008, and there were no sightings of him from that time until April 10, 2011, when he was observed at the Cathedral. So his mate is also his mother, which is by no means unheard of in the avian world.