AceShowbiz -

Rihanna was forced to back out of her concert in Boston because she was suffering from laryngitis. The gig was supposed to take place at TD Garden Sunday, March 10 as a second show of her "Diamonds" world tour after a rocking night at First Niagara Center in Buffalo on Friday.

"Unfortunately, following her sold-out concert on Friday," concert promoter giant Live Nation announced the cancellation in a statement, "Rihanna has contracted laryngitis and per doctor's instruction is unable to perform this evening."

RiRi herself took to Twitter to apologize to her devotees, "#BOSTON this is the hardest thing for me to deal with! I feel like we've been waiting on this day forever, and I'm hurt that I let you down," she said. "I hate disappointing people that never ever let me down!! I'm so embarrassed about this! Thank you for your prayers and well wishes!"

The Boston concert is rescheduled for a later date. She is expected to resume the tour on March 12 at 1st Mariner Arena in Baltimore.

She previously raved about her kick-off night in Buffalo, "Buffalo I will never forget how you made me feel tonight!!! Thank you from the bottom of my heart!! 1 (one) love always. Diamonds World Tour we (are) just getting started!!!" She also wrote, "You guys are all rock stars. There is only one first show, you all have a special place in my heart."