On Friday Adam flew to Madrid to talk to children who'd been affected by the bombings in the city.
Here he reports on the day, and talks about what some of the people he met were feeling about the attacks.
"Although some schools were open by lunchtime lots of schools had shut and students had come to demonstrate in one of Madrid's main squares.
It was massive and there were hundreds of school kids there. I asked them how they felt and most of them said they were angry that terrorists had struck in their city.
After that I headed down to Atocha, the station where the first bombs exploded on Thursday.
Candles at the station
First thing this morning there had been a few candles there but by mid-afternoon the number of candles had more than doubled.
It was very quiet there, even though the crowd was so big it was difficult to walk through the station.
Some of the people there looked very upset and you could really feel the sadness of the city.
I didn't get the feeling that people were scared. Most of the people I spoke to felt very angry towards the people who had set the bombs off.
Wash away sadness
One girl said she thought it was so terrible that innocent people had to die for other people's beliefs.
People also seemed to feel a bit strange because they don't know who to blame. Lots of people waved banners saying they were against the terrorist group Eta, although no one knows whether they planted the bombs.
Just before I left Madrid to head back to London it started to rain and someone said to me that it felt like the water was washing away some of the sadness."