(CNN)They're in their early 20s. They communicate and coordinate operations through a Telegram social media group. And they're helping to clean up Venice during its devastating floods.
How hundreds of young adults mobilized to clean up Venice amid devastating flooding
Hundreds of people descended on the flooded streets of the historic Italian city on Thursday to provide help to Venetians in difficulty -- draining houses or stores, moving household goods, collecting waste and sending it for recycling. Even more are on the ground Friday, after a high tide reached 5 feet, according to the organizers.
The volunteers are part of Venice Calls, an organization that has been active for more than a year, its spokesman, 25-year-old Piero Risica, told CNN.
"When we saw the historic flooding on Tuesday night, we immediately started to gather volunteers to help the city. The first day we were 200 in the Telegram group and on the ground. Yesterday 550, and today more than 1,700," Risica said.
While the Venice Calls core group is made of 35 people, all students between 18 and 25, Risica said hundreds of people from all age groups and from all over Italy responded to the call for help.
"We gather calls for help from Venetian residents through social media and word of mouth," Risica said. The group uses Telegram to coordinate operations, flag and geolocate addresses, fix appointments, and so on.
The main purpose is to clean up Venice from the surge waste that could have devastating effects for the lagoon ecosystem.
Working in coordination with the municipality, the group uses small boats to take away garbage that can be recycled, ANSA news agency reported.
"During the high water, people throw away garbage in the street out of necessity," Risica explains. "But that creates huge problems for the lagoon because it damages its ecosystem, so the lagoon is not able to heal itself and mitigate its problems.
"That's in addition to the pollution brought by men which kills the plants of the lagoon, such as the gigantic cruise ships. There are fewer natural barriers to defend the environment.
"But those are long-term problems, while we can work to solve the waste issue right now."
Group members help people recycle food, clothes and similar things that got soaked during the flood.
The young volunteers also helped rescue manuscripts and historic books at the music conservatory that were at risk of being lost forever.
And Italians have taken notice. A local resident on Facebook praised the group for "going around asking residents and commercial activities if they need help."
"It was a continual flow of young people with work gloves who dragged bags or pushed heavy carts full of garbage," he said in the post. "It was moving."