Jared Tucker and his wife had gone to Barcelona to celebrate their first anniversary in the form of a belated honeymoon. Walking in the area of the famous Las Ramblas boulevard on Thursday, he had gone to find a restroom when he was struck down by the van, his wife Heidi Nunes Tucker told KGO television in San Francisco.
"Pray for Jared and his family, pray for Barcelona, but most importantly pray that we can some day rid ourselves of the hate that takes our loved ones before their time," Tucker's family wrote in a statement posted on the Gofundme fundraising website.
Relatives started the fundraising effort to assist his family with living and educational expenses. Tucker lived in East Bay suburbs of San Francisco and is also survived by three daughters, KGO reported.
Earlier in the day, U.S. Secretary of State Rex Tillerson confirmed that an American citizen had been killed, but gave no other details.
The rampage through one of Spain's most popular tourist areas was the latest of a string of attacks across Europe in the past 13 months in which militants have used vehicles as weapons - a crude but deadly tactic that is near-impossible to prevent and has now killed nearly 130 people in France, Germany, Britain, Sweden and Spain.
Suspected terrorists have been behind the previous attacks. ISIS said the perpetrators of the latest one had been responding to its call to target countries involved in a U.S.-led coalition against the Sunni militant group.
The driver of the van may still be alive and at large, Spanish police said on Friday, denying earlier reports he had been killed. Five would-be attackers were shot dead by police in a seaside town.
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