Let me help with this translation.

Last week, some students from the Dorchester neighborhood of Boston visited the Museum of Fine Arts, where they subjected to "racist and disparaging comments and treatment from MFA staff and museum patrons," according to the principal of their school. 

The students in question were 7th graders (12 to 14 year olds), all students of color from the same middle school.  From the Globe article about this incident:

Forrest [the principal] said his staff has conveyed that one museum staff member reportedly told the academy students “no food, no drink, and no watermelon” at one point during the trip. There is a long history in this country of watermelon being used as a racist trope.

Forrest said he had heard other reports of museum security singling out students, following them as they progressed through exhibits while leaving white students alone.

Additionally, one museum patron reportedly made a comment to a female student about paying attention in the MFA so she could avoid a career as a stripper, while another patron referred to a group of students as “(expletive) black kids,” said Forrest.

A teacher on the trip:

Lamy also noticed museum staff closely followed the group of students she was with throughout the visit. Whenever the students would start moving, the staffers would start moving, and whenever they stopped, so did the workers, she said. 

And here are some excerpts from the "apology" that the museum posted on its web site:

 Last week, a number of students on an organized visit encountered a range of challenging and unacceptable experiences that made them feel unwelcome. That is not who we are or want to be. Our intention is to set the highest of standards, and we are committed to doing the work that it will take to get there.

Let me translate: for "encountered a range of challenging and unacceptable experiences that made them feel unwelcome" substitute "were treated in blatantly racist fashion by both staff and patrons at the MFA, an experience that is all too common for people of color in the United States."

For "That is not who we are or want to be," substitute "This happened because we have not properly trained our staff in how they are to behave and we have not trained them in how to recognize and deal with racist behavior in patrons."

You'l notice that the open letter never mentions racism. Amazing. It's a really crappy apology that doesn't name what has happened or mention the specific steps the MFA will take to ensure that this doesn't happen again. The letter doesn't mention the consequences for the staff members who behaved in a racist fashion and who failed to protect these children from the racist comments of other patrons.