Updated, 5:05 p.m. Sunday: Hailey Roser, 4, has met Justin Bieber.

Despite Children's Hospital being on lockdown because of the Brookfield mass shooting, she was allowed to leave the hospital and she met Bieber Sunday afternoon.

"Dreams come true," tweeted her family from the account @HealingHailey.

A Waukesha Patch Twitter follower told Patch that Hailey's ambulance arrived in Milwaukee for Bieber's concert.

"I am here with my daughters and the ambo with Hailey got here about 15 min ago," tweeted @brianokeefemke.

A social media campaign was launched last week to encourage Bieber to meet the 4-year-old girl, who is hospitalized in Wauwatosa. A local radio station had provided Hailey with tickets for a meet-and-greet show, according to the Facebook page.

Bieber planned to meet a young cancer patient before his concert Sunday, but a deadly mass shooting in Brookfield that prompted a lockdown at the Children's Hospital of Wisconsin put a temporary wrench in those plans.

Hailey, of Mukwonago, who was diagnosed with a rare form of cancer in August, was given permission to travel via ambulance to attend Bieber’s concert in Milwaukee. She was going to meet the pop star Sunday afternoon, but the lockdown was keeping people from leaving the hospital, according to a Facebook post.

"What are the chances????!!! Our thoughts and prayers are with the family and friends of all involved. :(," states the Healing Hailey Facebook page.

Waukesha Patch has left a voicemail with Children's Hospital seeking further information about the lockdown. Froedtert Hospital, adjacent to Children's, is also on lockdown.

Three people are confirmed dead in Sunday’s shooting at Azana Spa. Patients from the shooting were transported to Frodtert.