<Tr> <Th> 122 </Th> <Td> 20 </Td> <Td> "Hook, Line and Sinner" </Td> <Td> Tony Phelan </Td> <Td> Meg Marinis </Td> <Td> April 29, 2010 (2010 - 04 - 29) </Td> <Td> 10.47 </Td> </Tr> <Tr> <Td_colspan="7"> Teddy is getting more involved with Mark, to get over Owen, but Mark's daughter arrives at his house unexpectedly and in labor . Mark wants to keep the baby, and asks Torres for guidance while getting some unwanted advice from Arizona . Meredith begins to notice Dr. Kepner's crush on Derek . </Td> </Tr> <Tr> <Th> 123 </Th> <Td> 21 </Td> <Td> "How Insensitive" </Td> <Td> Tom Verica </Td> <Td> William Harper </Td> <Td> May 6, 2010 (2010 - 05 - 06) </Td> <Td> 11.03 </Td> </Tr> <Tr> <Td_colspan="7"> Bailey preps the team with mandatory sensitivity training prior to admitting a 700 - pound patient with compounded medical issues, and the case proves to be challenging in every sense of the word . Meanwhile Derek has to come face to face with a former patient's husband in a wrongful death deposition, and spending time with a heart patient's daughter opens up some old wounds for Cristina . </Td> </Tr>

What episode did the shooting happened in grey's anatomy