Jets Hit 10 Miles From HaiphongSAIGON, April 20 lt;AP) - U.S. Navy bombers ct\uvQ closer ?u Hafphung Tuesday in Uui Ihird straight dwy of mid* on Nor Lb Viet Nam's vital Hod RiverDelta. blnMing o railroad bridcc JO miles north of lire counirjTB chief port. A U.K. RpokcRmun Said duo span of Hit? bridge wag destroyed,Four Soviet-built surfaced#-air missiles were tired ul the attackers but missed their marks, the spokesman reporled. Three other U.S. jets werelost elsewhere over North Vlel Nii in, raising the number Of American planes shot down since Hi#- raids began lfl mauLhe ago to 21ft. One of Utc pUale was iTstunl in li blaze of enemy tire. The other iwo were jareiuniLii captured or dead.In the south, Vlel Cun* raiders tiuttULgrd two liig U.S, Air Force Hercules troop trarsporls lit a hit-und-rim attack on a small airfield in the central highlands hut caused w casual-tins. Officials said the faur-eh-Elui? pluiir-5 could be rciMlTcd.Allied Jo ret e r^p#rl r-d ILtlk other «iincaoC wlih the Coirunu-ntsfs as Lise hull Jn me gro^md wwr tonfjpiucd. Only Jkiufch Korean furcut rr-isirmd u brails or =iay significance, In a sw«n onElm tTii1r;il vnuKl,The raid near IT;ii|riurtg followed up on ulfcHck by Nuvy bombers on the Urnur EL power plant 14 miCes. nnrchwisc or Che cfcty Monday ni«hLThe Navy plfoss rclurnEne from the new raid* on 1he Hal-Dirksen Proposal RejectedRemap Amendment FizzlesWASHINGTON, April 20 (APIjposat by Republican Leader Ev-A DrnivTAprl hm^tihitinnnl nniprA* I oroit Ti. Dirksen of Illinois. Ahave gK-rmiLEcd gMErapity and ncllliCftl S.1l1vll Vkinrtc in iirldHlmililionfi-IIaiioi area reported (bat hluhwuy traffic between thecfetes had been virltiuJly hailed,I he jsfKjkfcKttiuH *uld.Oilier Alt Force nnd Nuvy Ju1« hjittored a wide rnnnv at coniiHfcUrltiilioji inrgels up and 4fcrt*rn the North VictitfJmcst jmnbaiidle- Pi lota report ed culling rands In 10 plncc-fi, crater cits a river ford, destroying an an-I [aircraft position and u highway brtdge and blusting four truck parks.An Air Force F105 Thunder-chief was shot down by automatic weapons fire near Dong HoL The pilot did not eject and was presumed dead.The Strategic Air Coitid's BSSa cume Sn from Guam for whnt spokesmen called a moderate* me strike against Communist/Conf. On Pago £\, Col. JJin 11.