 Donna has appeared in two editions of Casualty @ Holby City — crossovers with Holby City 's sister show Casualty , which is set in the hospital 's emergency department ( ED ) . In the first such crossover , originally broadcast in December 2004 , Donna works alongside ED staff members when a fuel tanker crashes into the hospital . She reappears in the fourth edition of Casualty @ Holby City , originally broadcast in December 2005 , when she is involved in a car crash en route to the staff Christmas party . She and paramedic Paul " Woody " Joyner ( Will Thorp ) then inadvertently cause a tunnel to collapse while trying to rescue a trapped baby . In 2010 , Donna appeared in Casualty itself , for the launch of the show 's twenty @-@ fifth series . She was included in the episode at the bequest of its writer , Mark <unk> . Casualty 's series producer Oliver Kent deemed her " hilariously funny " and " one of Holby 's best characters " . During the episode , the ED staff work through the aftermath of a school shooting . Jacobs explained that Donna finds the shift difficult and is " really quite scared " , as she is used to working with routine rather than emergency patients . In contrast to her typical disorganisation and laziness , Donna is forced to work hard and " put herself on the line " to keep up with the other staff members . 
