Is this true? Is there a source link?
No, it’s not true. There are plenty of stories from a week before the shelling about how they moved most of their patients to the basement of the maternity hospital, so it was in operation. Obviously they still had some people on the surface as people came and went, for admission, etc. They were operating a maternity ward, nursery, and treating other injured people.
For example (last 3 pics are the Mariupol hospital, first ones are a hospital in Kyiv),
https://www.channelnewsasia.com/world/ukraine-russia-invasion-maternity-ward-shelter-basement-2531881#:~:text=The%20basement%20of%20the%20maternity,on%20Tuesday%20(Mar%201).
You can also search for:
ukrainian maternity ward moved to basement for shelter
mariupol hospital basement
The Russians are trying to capture cities. In the process, civilians will die. This shouldn’t be surprising but when it happens to kids, patients, or pregnant women it’s labeled fake because it makes Russia look bad, even though they will be some portion of the war dead. It’s also possible that there were Ukrainian forces in the area since they’re defending the city and use buildings to do that. It could also have just been a targeting mistake.
You can go read the internet of the past two days and find it pretty quickly.