A week ago Thursday, a van mowed down people walking on Barcelona's famed Las Ramblas promenade, killing 13 people and injuring more than 100 others.

A team of Associated Press photographers followed the story from the initial attack to a second after midnight in nearby Cambrils, the investigation at a suspected bomb-making house in Alcanar, the hunt for the Las Ramblas van driver, and the expressions of grief and mourning by Spanish VIPs, local people and foreign tourists.

The eventual death toll was 15, including a woman killed in Cambrils and a man carjacked by one of the suspects.

When screams and shouts echoed around Las Ramblas, panicked people in the summer crowd began to flee into side streets. At that moment, nobody knew an extremist cell was executing a planned attack by using a speeding van as a weapon. Children were among those caught up in the incident.

Emergency services swiftly converged on the scene. They treated the injured left sprawled on the ground along the pedestrian zone. The picturesque area had been turned into a bloody killing zone.

Far-right protesters arrived Friday at the scene and argued with some of the mourners gathered on Las Ramblas. Frightened onlookers ducked into stores.

In the early hours of Friday, an Audi plowed into pedestrians on the promenade in Cambrils, a coastal town south of Barcelona. Police shot all five attackers dead. Investigators believe they belonged to the same cell responsible for the Las Ramblas incident.

After the two attacks, investigators turned their attention back to a house in Alcanar, 200 kilometers (125 miles) down the coast from Barcelona, where a blast last Wednesday was initially attributed to an accidental gas explosion. Investigators went back through the wreckage, finding equipment that included more than 100 tanks of butane gas, nails, and 500 liters of a highly flammable liquid often used in Islamic State group bombs.

On Las Ramblas, well-wishers started an impromptu memorial, placing candles on the ground. It gradually grew in size as people added more candles, flowers and written messages.

Spanish King Felipe VI, Queen Letizia and Catalan regional President Carles Puigdemont were among the VIP visitors to the memorial, where people wept and gathered to pray and pay their respects.

The Muslim community in Ripoll, a town in the Pyrenees foothills where most of the other suspects lived, expressed grief and dismay at the attacks and said they rejected violence.

A Sunday Mass in memory of the victims was held at Barcelona's famous Sagrada Familia basilica.

The same day, a minute of silence was observed before Barcelona football team's game at its Camp Nou stadium.

On Monday, four days after the attacks, weeping people were still gathering at the Las Ramblas memorial.