Summary: Tuesday on the NewsHour, President Biden grieves with families of those killed in the mass shooting in Buffalo, calling out the attack as terrorism inspired by the "poison" of white supremacy. Then, Ukrainian fighters leave a steel plant in the city of Mariupol. Also, Russia's invasion of Ukraine threatens its decades-long partnership with NASA and the future of the International Space Station. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders
