Starting May 13, DL will consolidate service to a single airport in multi-airport regions. Service will be suspended until at least September.

BOS suspending MHT & PVD
CLE suspending CAK
JFK suspending SWF & HPN
LAX suspending BUR & LGB
LGA suspending HPN
ORD suspending MDW
ORF suspending PHF
SFO suspending OAK


https://news.delta.com/delta-temporarily-consolidate-flying-select-us-metros