MNP Tower as West National City Bank
Maggie is trying to negotiate with some band robbers who took hostages when Kara bursts in through the roof and takes them out herself.
“Alex” Filming Locations
Kara and Maggie are in a race against time when Alex is kidnapped by someone from the Danvers sisters' childhood and Rhea approaches Lena with some tantalizing technology.
Supergirl episode “Alex” was filmed in Vancouver in Canada.
Ellis Residence as Rick Malverne's House
Kara returns to the home of Rick Malverne where she finds a computer watching Alex and confronts Malverne.
Source: richardwalker00 — Twitter
Johnstone Boiler & Tank Ltd. as Wrong Warehouse
Kara heads the warehouse indicated by Alex's tracker but only finds a trap set by Rick Malverne.
Source: FloriansEdits — Twitter