A deathly silence filled the air as the Spanish capital came to a halt at noon today, writes Aoife O'Reillyin Madrid.
Thousands of people stopped work for 15 minutes to express their solidarity with the victims of yesterday's bomb attacks that killed 198 people and injured almost 1,500.
The silence was broken only by the sound of police sirens and helicopters overhead, as people stood in the drizzle to show their support for the victims, the constitution and for "the defeat of terrorism".
Spaniards take to the streets and demonstrate in Madrid's Puerta del Sol today
Faces grim and pale, some held their hands in prayer and bowed their heads. Others stood defiant with their hands clasped behind their backs - all united by the sense of loss and devastation that has overtaken the city in the last 24 hours.
The walkout was called for by the main worker's unions and was supported by cultural, enterprise, social, human rights and immigrants' organisations.
On the busy street of Princesa in the centre of Madrid, crowds spilled from the department store El Corte Ingles, clothes shop Zara, and the surrounding shops and businesses, to join the demonstration. Women held on to each other in support, and men looked ahead subdued as the silence was observed.
El Corte Ingles employees held up a banner saying "Los Traba Jadores De Contra El Atentado Terrorism" (a call for unity against terrorism). An employee, José Maria, said the focus now must be on helping the victims, then the government must act to find those responsible.
"Yesterday was the worst day I ever lived in my life," he said. "All the people in Madrid feel the same."
Cesar Sanchez Delgado spoke of the city's confusion and pain. "The government must call for calm because everybody feels the same sadness and confusion, then we can look for those responsible. The most important thing now is calm and tranquillity," he told ireland.com.
Throughout the city, there were similar scenes of grief and mourning. On the main street of Gran Via, crowds left work to join pedestrians on the pavements. Some ran onto the street to stop the traffic, while many motorists left their cars to show their support.
A resounding round of applause ended the demonstration and people slowly went back to work. Shops and businesses are to close early at 6.30 p.m. (5.30 p.m. Irish time) to attend the mass demonstrations at Colon in the centre of Madrid.