By Susan Cornwell, Linda So, Michael Berens, Andrea Janutaand Joseph Tanfani

Jan 8 (Reuters) - As the mob swarmed into the U.S. Capitol,Pennsylvania congresswoman Susan Wild took cover, squeezing intoa tight aisle in an upper-floor gallery and inching across thefloor as supporters of President Donald Trump banged on thedoors.

That was when it really started to get scary, said Wild,63, describing Wednesdays dramatic siege of the complex thathouses the U.S. Congress. After she fumbled to work a gas maskand briefly lost a shoe while dragging herself toward a door toevacuate, gunfire rang out. Police shouted, Get down. Get down.Get down! as people screamed, Wild said in an interview withReuters.

Moments earlier, as hundreds of rioters stormed thebuilding, U.S. Capitol Police officers barricaded the lawmakersinside the chamber of the House of Representatives, where theyhad just started the final certification of electoral votesshowing Democrat Joe Biden had beaten Trump in the Novemberelection.

It wasnt until things really escalated that there was akind of a panicky state, said the Pennsylvania Democrat.

A day after the historic security breach of the iconic domedbuilding that houses the U.S. House and Senate, lawmakers toldharrowing tales of their escapes from grave danger in the deadlymob assault that many say was incited by Trump. Several toldReuters that top Capitol security officials had assured themthey would be safe ahead of the planned protests and thateverything was under control.

As recriminations began in Congress, officials at otherbranches of government said they could have provided more peopleto secure the Capitol but no one from the Capitol Policeasked. A senior U.S. defense official said that the Pentagon hadbeen in touch with the Capitol police last week and as late asSunday but were told that they would not require assistance fromthe National Guard.

"We asked more than once, and the final return that we goton Sunday, January 3, was that they would not be asking DOD(the Department of Defense) for assistance," said KennethRapuano, assistant secretary of defense for homeland defense andglobal security.

The siege that left five people dead, including a policeofficer, and up to 60 officers injured, prompted lawmakers todemand an investigation into security lapses. Fallout has beenswift. The Capitol Police chief will resign. House Speaker NancyPelosi said the House sergeant at arms would resign. And topSenate Democrat Chuck Schumer said he would fire the Senatesergeant at arms.

In interviews with Reuters and in public statements,lawmakers fumed over the failure of the Capitol Police - a2,000-member force dedicated to guarding the Capitol Grounds -and other agencies. Lindsey Graham, one of Trumps closestallies and chief defenders, said the invaders, many carryingweapons or unsearched backpacks, could have blown the buildingup. They could have killed us all. They could have destroyed thegovernment.

How could we not be prepared he asked at a newsconference. If the Capitol Police had been in the military, hesaid, they would have been relieved of their commands and mostlikely court-martialed and tried for crimes in a militarycourt.

Capitol Police did not respond to a request for comment onThursday evening. Earlier in the day, U.S. Capitol Police ChiefSteven Sund released a statement praising his officers responseto an overwhelming situation. The department, he said, had arobust plan to handle anticipated First Amendmentactivities.

Sund, who on Thursday agreed to resign, described the massriots as criminal and said the officers were heroic giventhe situation.

DOING THE BEST WE CAN

For weeks, Trump had urged supporters to show up for awild march to Save America in the nations capital on Jan.6. In his speech that day, he repeated baseless claims of voterfraud in the election won by Democrat Joe Biden and exhorted hissupporters to fight.

Despite danger signs leading up to Trumps rally, severallawmakers told Reuters that top Capitol security officials hadassured them in meetings they did not expect violence at theevent. No one could get on the Capitol grounds and police hadplenty of manpower to handle any incidents, the lawmakers saidsecurity officials told them.

Maxine Waters, Chairwoman of the House Financial ServicesCommittee, said she had repeatedly warned Police Chief Sund andother police officials about growing evidence that right-wingextremist groups such as the Proud Boys and Oath Keepers plannedto descend on the nations capital. There had been pervasivechatter on the web and social media platforms, she said, focusedon how these groups would try to sneak weapons into the Districtof Columbia.

The California Democrat said she initiated a one-hourtelephone call with Sund on Dec. 31. They had assured us thateverything would be under control, Waters told Reuters in aninterview.

She called Sund again during the riots, while barricaded inher office with her staff. She said she was frightened andfurious at the lack of communication from police. Sund offeredlittle comfort, she said.

As she watched the events unfold on the television in heroffice, Waters described the scenes to the chief as they talked.The chief, who seemed calm, told Waters several times, We aredoing the best we can. She responded: Its not good enough,and hung up.

Reuters was unable to reach Sund for comment Thursdayevening.

Tim Ryan, a Democratic Representative from Ohio, was workingin his Capitol office when the mob stormed the building onWednesday. He said that ahead of Trumps rally, he too hadconversations with the Capitol Police chief and the Senatessergeant at arms, who both assured him they werent anticipatingviolence and had taken precautions to keep demonstrators awayfrom the Capitol.

The next thing you know, you turn on the TV and theyreswinging from the Capitol building with flags, Ryan said in avideo news conference with reporters.

Ryan questioned whether officials performed an adequatethreat assessment and intelligence gathering ahead of theplanned protests. He said he expressed concerns about possibleviolence to the top Capitol security officials leading up to theevent, but was told the protests would be pretty vanilla withmaybe some dustups.

OFFERS OF HELP TURNED AWAY

Army Secretary Ryan McCarthy said that there had been nomilitary contingency planning for the Capitol because theCapitol Police had not made any requests in the lead-up to theprotests.

Defense officials also said that intelligence reportsprovided by law enforcement did not suggest any threats of thekind of violence that broke out Wednesday. The reportsestimates of expected crowds varied wildly - from 2,000 to80,000, they said.

"It was all over the board, McCarthy said, noting themilitary relies on law enforcement for information on potentialthreats in a protest. So it was very challenging.

The actual turnout was difficult to estimate but crowdsnumbered in the thousands, enough to easily overwhelm policewhen the Capitol was stormed.

Rapuano said there had been some mention of social mediadiscussions on pro-Trump online forums about Jan. 6demonstrations during interagency meetings that were chaired bythe Department of Justice. But "overall the assessment that wegot repeatedly was no indication of significant, significantviolent protest."

Sources familiar with planning at the Homeland Security andJustice departments also said the agencies were not asked toprovide security forces for the Capitol beforehand, in contrastto their deployment during last summers racial justiceprotests. The Justice Department sent 500 law enforcementofficers from the Federal Bureau of Investigation and four otheroffices to the Capitol on Wednesday but only after the riotingwas under way.

Former Washington Police Chief Charles Ramsey said thebreach reflected poor planning and a failure of leadership.

The outside of the Capitol shouldve looked like a scenefrom the Game of Thrones, Ramsey told Reuters, referring tothe popular - and violent - television series. They wouldvealready been on the ground and had the gear on. They wouldvebeen ready.

INADEQUATE WARNINGS

Congresswoman Nikema Williams had arrived on Sunday at theCapitol for her first day as Georgias newly elected Democraticrepresentative. She remembered staring up at the ceilings andtaking pictures, thinking, Im in a building where I feelsecure and safe, and nobodys getting through here, she toldReuters.

That sense of security was shattered days later. She arrivedearly on Wednesday to avoid the expected crowds and wasntconcerned. She was watching the vote on a TV in her office andrealized something was wrong when she saw House Speaker NancyPelosi escorted away.

She said the official security emails were vague and lackedspecifics about what was happening. If it hadnt been forTwitter, and the group texts and emails that I was in, I wouldnot have any information, she said.

New Congressman Jamaal Bowman, a Democrat, said he hadstronger security protocols and briefings at a New York Citymiddle school where he served as principal. He said members ofCongress were advised to arrive at their offices early and stayinside the buildings because of the expected protests, butreceived no security briefings and no communication aboutpossible dangers inside the building.

It was a debacle, he said. To come to Congress, whichshould be the most secure place in the country, and be here forthree days and the Capitol gets breached, Im blown away.

(Reporting by Susan Cornwell, Linda So, Michael Berens andAndrea JanutaAdditional reporting by Joseph Tanfani, John Shiffman, IdreesAli and Mark HosenballEditing by Jason Szep and Brian Thevenot) ((susan.cornwell@thomsonreuters.com linda.so@thomsonreuters.com michael.berens@thomsonreuters.comandrea.januta@thomsonreuters.com))